diff --git a/e2e_tests/test_worktrees.py b/e2e_tests/test_worktrees.py
index 1ded432..b2d21a3 100644
--- a/e2e_tests/test_worktrees.py
+++ b/e2e_tests/test_worktrees.py
@@ -4,92 +4,487 @@ from helpers import *
 
 import git
 import pytest
+import datetime
 
 import os.path
 
 
+@pytest.mark.parametrize("config_enabled", [True, False])
+@pytest.mark.parametrize("config_has_default_remote_prefix", [True, False])
+@pytest.mark.parametrize("config_has_default_track_enabled", [True, False])
+@pytest.mark.parametrize("explicit_notrack", [True, False])
+@pytest.mark.parametrize("explicit_track", [True, False])
+@pytest.mark.parametrize("local_branch_exists", [True, False])
+@pytest.mark.parametrize("local_branch_has_tracking_branch", [True, False])
 @pytest.mark.parametrize("remote_branch_already_exists", [True, False])
-@pytest.mark.parametrize("has_config", [True, False])
-@pytest.mark.parametrize("has_default", [True, False])
-@pytest.mark.parametrize("has_prefix", [True, False])
+@pytest.mark.parametrize("remote_branch_with_prefix_already_exists", [True, False])
+@pytest.mark.parametrize(
+    "remote_setup",
+    (
+        (0, "origin", False),
+        (1, "origin", False),
+        (2, "origin", False),
+        (2, "otherremote", False),
+        (2, "origin", True),
+        (2, "otherremote", True),
+    ),
+)
+@pytest.mark.parametrize("track_differs_from_existing_branch_upstream", [True, False])
 @pytest.mark.parametrize("worktree_with_slash", [True, False])
 def test_worktree_add(
+    config_enabled,
+    config_has_default_remote_prefix,
+    config_has_default_track_enabled,
+    explicit_notrack,
+    explicit_track,
+    local_branch_exists,
+    local_branch_has_tracking_branch,
     remote_branch_already_exists,
-    has_config,
-    has_default,
-    has_prefix,
+    remote_branch_with_prefix_already_exists,
+    remote_setup,
+    track_differs_from_existing_branch_upstream,
     worktree_with_slash,
 ):
+    (remote_count, default_remote, remotes_differ) = remote_setup
+    has_remotes = True if remote_count > 0 else False
+
     if worktree_with_slash:
-        worktree_name = "dir/test"
+        worktree_name = "dir/nested/test"
     else:
         worktree_name = "test"
-    with TempGitRepositoryWorktree() as (base_dir, _commit):
-        if has_config:
+
+    if track_differs_from_existing_branch_upstream:
+        explicit_track_branch_name = f"{default_remote}/somethingelse"
+    else:
+        explicit_track_branch_name = f"{default_remote}/{worktree_name}"
+
+    timestamp = datetime.datetime.now().replace(microsecond=0).isoformat()
+    # GitPython has some weird behaviour here. It is not possible to use kwargs
+    # to set the commit and author date.
+    #
+    # `committer_date=x` (which is documented) does not work, as `git commit`
+    # does not accept --committer-date
+    #
+    # `author_date=x` does not work, as it's now called --date in `git commit`
+    #
+    # `date=x` should work, but is refused by GitPython, as it does not know
+    # about the new behaviour in `git commit`
+    #
+    # Fortunately, there are env variables that control those timestamps.
+    os.environ["GIT_COMMITTER_DATE"] = str(timestamp)
+    os.environ["GIT_AUTHOR_DATE"] = str(timestamp)
+
+    def setup_remote1(directory):
+        if remote_branch_already_exists:
+            with tempfile.TemporaryDirectory() as cloned:
+                repo = git.Repo.clone_from(directory, cloned)
+                newfile = os.path.join(cloned, "change")
+                open(newfile, "w").close()
+                repo.index.add([newfile])
+                repo.index.commit("commit")
+                repo.remotes.origin.push(f"HEAD:{worktree_name}", force=True)
+
+        if remote_branch_with_prefix_already_exists:
+            with tempfile.TemporaryDirectory() as cloned:
+                repo = git.Repo.clone_from(directory, cloned)
+                newfile = os.path.join(cloned, "change2")
+                open(newfile, "w").close()
+                repo.index.add([newfile])
+                repo.index.commit("commit")
+                repo.remotes.origin.push(f"HEAD:myprefix/{worktree_name}", force=True)
+
+        return "_".join(
+            [
+                str(worktree_with_slash),
+                str(remote_branch_already_exists),
+                str(remote_branch_with_prefix_already_exists),
+                str(remotes_differ),
+            ]
+        )
+
+    def setup_remote2(directory):
+        if remote_branch_already_exists:
+            with tempfile.TemporaryDirectory() as cloned:
+                repo = git.Repo.clone_from(directory, cloned)
+                newfile = os.path.join(cloned, "change")
+                open(newfile, "w").close()
+                repo.index.add([newfile])
+                repo.index.commit("commit")
+                if remotes_differ:
+                    newfile = os.path.join(cloned, "change_on_second_remote")
+                    open(newfile, "w").close()
+                    repo.index.add([newfile])
+                    repo.index.commit("commit_on_second_remote")
+                repo.remotes.origin.push(f"HEAD:{worktree_name}", force=True)
+
+        if remote_branch_with_prefix_already_exists:
+            with tempfile.TemporaryDirectory() as cloned:
+                repo = git.Repo.clone_from(directory, cloned)
+                newfile = os.path.join(cloned, "change2")
+                open(newfile, "w").close()
+                repo.index.add([newfile])
+                repo.index.commit("commit")
+                if remotes_differ:
+                    newfile = os.path.join(cloned, "change_on_second_remote2")
+                    open(newfile, "w").close()
+                    repo.index.add([newfile])
+                    repo.index.commit("commit_on_second_remote2")
+                repo.remotes.origin.push(f"HEAD:myprefix/{worktree_name}", force=True)
+
+        return "_".join(
+            [
+                str(worktree_with_slash),
+                str(remote_branch_already_exists),
+                str(remote_branch_with_prefix_already_exists),
+                str(remotes_differ),
+            ]
+        )
+
+    cachefn = lambda nr: "_".join(
+        [
+            str(nr),
+            str(default_remote),
+            str(local_branch_exists),
+            str(remote_branch_already_exists),
+            str(remote_branch_with_prefix_already_exists),
+            str(remote_count),
+            str(remotes_differ),
+            str(worktree_name),
+        ]
+    )
+    remote1_cache_key = cachefn(1)
+    remote2_cache_key = cachefn(2)
+
+    cachekey = "_".join(
+        [
+            str(local_branch_exists),
+            str(local_branch_has_tracking_branch),
+            str(remote_branch_already_exists),
+            str(remote_branch_with_prefix_already_exists),
+            str(remote_count),
+            str(remotes_differ),
+            str(worktree_name),
+        ]
+    )
+
+    with TempGitRepositoryWorktree.get(
+        cachekey=cachekey,
+        branch=worktree_name if local_branch_exists else None,
+        remotes=remote_count,
+        remote_setup=[
+            [remote1_cache_key, setup_remote1],
+            [remote2_cache_key, setup_remote2],
+        ],
+    ) as (base_dir, initial_commit):
+        repo = git.Repo(os.path.join(base_dir, ".git-main-working-tree"))
+
+        if config_enabled:
             with open(os.path.join(base_dir, "grm.toml"), "w") as f:
                 f.write(
                     f"""
-                [track]
-                default = {str(has_default).lower()}
-                default_remote = "origin"
-                """
+                        [track]
+                        default = {str(config_has_default_track_enabled).lower()}
+                        default_remote = "{default_remote}"
+                        """
                 )
-                if has_prefix:
+
+                if config_has_default_remote_prefix:
                     f.write(
                         """
                     default_remote_prefix = "myprefix"
                     """
                     )
 
-        if remote_branch_already_exists:
-            shell(
-                f"""
-                cd {base_dir}
-                git --git-dir ./.git-main-working-tree worktree add tmp
-                (
-                    cd tmp
-                    touch change
-                    git add change
-                    git commit -m commit
-                    git push origin HEAD:{worktree_name}
-                    #git reset --hard 'HEAD@{1}'
-                    git branch -va
-                )
-                git --git-dir ./.git-main-working-tree worktree remove tmp
-            """
-            )
-        cmd = grm(["wt", "add", worktree_name], cwd=base_dir)
+        if local_branch_exists:
+            if has_remotes and local_branch_has_tracking_branch:
+                origin = repo.remote(default_remote)
+                if remote_count >= 2:
+                    otherremote = repo.remote("otherremote")
+                br = list(filter(lambda x: x.name == worktree_name, repo.branches))[0]
+                assert os.path.exists(base_dir)
+                if track_differs_from_existing_branch_upstream:
+                    origin.push(
+                        f"{worktree_name}:someothername", force=True, set_upstream=True
+                    )
+                    if remote_count >= 2:
+                        otherremote.push(
+                            f"{worktree_name}:someothername",
+                            force=True,
+                            set_upstream=True,
+                        )
+                    br.set_tracking_branch(
+                        list(
+                            filter(
+                                lambda x: x.remote_head == "someothername", origin.refs
+                            )
+                        )[0]
+                    )
+                else:
+                    origin.push(
+                        f"{worktree_name}:{worktree_name}",
+                        force=True,
+                        set_upstream=True,
+                    )
+                    if remote_count >= 2:
+                        otherremote.push(
+                            f"{worktree_name}:{worktree_name}",
+                            force=True,
+                            set_upstream=True,
+                        )
+                    br.set_tracking_branch(
+                        list(
+                            filter(
+                                lambda x: x.remote_head == worktree_name, origin.refs
+                            )
+                        )[0]
+                    )
+
+        args = ["wt", "add", worktree_name]
+        if explicit_track:
+            args.extend(["--track", explicit_track_branch_name])
+        if explicit_notrack:
+            args.extend(["--no-track"])
+        cmd = grm(args, cwd=base_dir)
+        if explicit_track and not explicit_notrack and not has_remotes:
+            assert cmd.returncode != 0
+            assert f'remote "{default_remote}" not found' in cmd.stderr.lower()
+            return
         assert cmd.returncode == 0
 
+        assert len(cmd.stdout.strip().split("\n")) == 1
+        assert f"worktree {worktree_name} created" in cmd.stdout.lower()
+
+        def check_deviation_error(base):
+            if (
+                not local_branch_exists
+                and (explicit_notrack or (not explicit_notrack and not explicit_track))
+                and (
+                    remote_branch_already_exists
+                    or (
+                        config_enabled
+                        and config_has_default_remote_prefix
+                        and remote_branch_with_prefix_already_exists
+                    )
+                )
+                and remote_count >= 2
+                and remotes_differ
+            ):
+                assert (
+                    f"branch exists on multiple remotes, but they deviate"
+                    in cmd.stderr.lower()
+                )
+                assert len(cmd.stderr.strip().split("\n")) == base + 1
+            else:
+                if base == 0:
+                    assert len(cmd.stderr) == base
+                else:
+                    assert len(cmd.stderr.strip().split("\n")) == base
+
+        if explicit_track and explicit_notrack:
+            assert "--track will be ignored" in cmd.stderr.lower()
+            check_deviation_error(1)
+        else:
+            check_deviation_error(0)
+
         files = os.listdir(base_dir)
-        if has_config is True:
+        if config_enabled is True:
+            if worktree_with_slash:
+                assert set(files) == {".git-main-working-tree", "grm.toml", "dir"}
+            else:
+                assert set(files) == {".git-main-working-tree", "grm.toml", "test"}
             assert len(files) == 3
             if worktree_with_slash:
                 assert set(files) == {".git-main-working-tree", "grm.toml", "dir"}
-                assert set(os.listdir(os.path.join(base_dir, "dir"))) == {"test"}
+                assert set(os.listdir(os.path.join(base_dir, "dir"))) == {"nested"}
+                assert set(os.listdir(os.path.join(base_dir, "dir/nested"))) == {"test"}
             else:
                 assert set(files) == {".git-main-working-tree", "grm.toml", "test"}
         else:
             assert len(files) == 2
             if worktree_with_slash:
                 assert set(files) == {".git-main-working-tree", "dir"}
-                assert set(os.listdir(os.path.join(base_dir, "dir"))) == {"test"}
+                assert set(os.listdir(os.path.join(base_dir, "dir"))) == {"nested"}
+                assert set(os.listdir(os.path.join(base_dir, "dir/nested"))) == {"test"}
             else:
                 assert set(files) == {".git-main-working-tree", "test"}
 
         repo = git.Repo(os.path.join(base_dir, worktree_name))
         assert not repo.bare
-        assert not repo.is_dirty()
-        if has_config and has_default:
-            if has_prefix and not remote_branch_already_exists:
+        # assert not repo.is_dirty()
+        assert str(repo.head.ref) == worktree_name
+
+        local_commit = repo.head.commit.hexsha
+
+        if not has_remotes:
+            assert local_commit == initial_commit
+        elif local_branch_exists:
+            assert local_commit == initial_commit
+        elif explicit_track and not explicit_notrack:
+            assert local_commit == repo.commit(explicit_track_branch_name).hexsha
+        elif explicit_notrack:
+            if config_enabled and config_has_default_remote_prefix:
+                if remote_branch_with_prefix_already_exists:
+                    assert (
+                        local_commit
+                        == repo.commit(
+                            f"{default_remote}/myprefix/{worktree_name}"
+                        ).hexsha
+                    )
+                elif remote_branch_already_exists:
+                    assert (
+                        local_commit
+                        == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                    )
+                else:
+                    assert local_commit == initial_commit
+            elif remote_count == 1:
+                if config_enabled and config_has_default_remote_prefix:
+                    if remote_branch_with_prefix_already_exists:
+                        assert (
+                            local_commit
+                            == repo.commit(
+                                f"{default_remote}/myprefix/{worktree_name}"
+                            ).hexsha
+                        )
+                    elif remote_branch_already_exists:
+                        assert (
+                            local_commit
+                            == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                        )
+                    else:
+                        assert local_commit == initial_commit
+                elif remote_branch_already_exists:
+                    assert (
+                        local_commit
+                        == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                    )
+                else:
+                    assert local_commit == initial_commit
+            elif remotes_differ:
+                if config_enabled:  # we have a default remote
+                    if (
+                        config_has_default_remote_prefix
+                        and remote_branch_with_prefix_already_exists
+                    ):
+                        assert (
+                            local_commit
+                            == repo.commit(
+                                f"{default_remote}/myprefix/{worktree_name}"
+                            ).hexsha
+                        )
+                    elif remote_branch_already_exists:
+                        assert (
+                            local_commit
+                            == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                        )
+                    else:
+                        assert local_commit == initial_commit
+                else:
+                    assert local_commit == initial_commit
+
+            else:
+                if config_enabled and config_has_default_remote_prefix:
+                    if remote_branch_with_prefix_already_exists:
+                        assert (
+                            local_commit
+                            == repo.commit(
+                                f"{default_remote}/myprefix/{worktree_name}"
+                            ).hexsha
+                        )
+                    elif remote_branch_already_exists:
+                        assert (
+                            local_commit
+                            == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                        )
+                    else:
+                        assert local_commit == initial_commit
+
+        elif config_enabled:
+            if not config_has_default_remote_prefix:
+                if config_has_default_track_enabled:
+                    assert (
+                        local_commit
+                        == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                    )
+                else:
+                    if remote_branch_already_exists:
+                        assert (
+                            local_commit
+                            == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                        )
+                    else:
+                        assert local_commit == initial_commit
+            else:
+                if remote_branch_with_prefix_already_exists:
+                    assert (
+                        local_commit
+                        == repo.commit(
+                            f"{default_remote}/myprefix/{worktree_name}"
+                        ).hexsha
+                    )
+                elif remote_branch_already_exists:
+                    assert (
+                        local_commit
+                        == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+                    )
+                elif config_has_default_track_enabled:
+                    assert (
+                        local_commit
+                        == repo.commit(
+                            f"{default_remote}/myprefix/{worktree_name}"
+                        ).hexsha
+                    )
+                else:
+                    assert local_commit == initial_commit
+        elif remote_branch_already_exists and not remotes_differ:
+            assert (
+                local_commit == repo.commit(f"{default_remote}/{worktree_name}").hexsha
+            )
+        else:
+            assert local_commit == initial_commit
+
+        # Check whether tracking is ok
+        if not has_remotes:
+            assert repo.active_branch.tracking_branch() is None
+        elif explicit_notrack:
+            if local_branch_exists and local_branch_has_tracking_branch:
+                if track_differs_from_existing_branch_upstream:
+                    assert (
+                        str(repo.active_branch.tracking_branch())
+                        == f"{default_remote}/someothername"
+                    )
+                else:
+                    assert (
+                        str(repo.active_branch.tracking_branch())
+                        == f"{default_remote}/{worktree_name}"
+                    )
+            else:
+                assert repo.active_branch.tracking_branch() is None
+        elif explicit_track:
+            assert (
+                str(repo.active_branch.tracking_branch()) == explicit_track_branch_name
+            )
+        elif config_enabled and config_has_default_track_enabled:
+            if config_has_default_remote_prefix:
                 assert (
                     str(repo.active_branch.tracking_branch())
-                    == f"origin/myprefix/{worktree_name}"
+                    == f"{default_remote}/myprefix/{worktree_name}"
                 )
             else:
                 assert (
                     str(repo.active_branch.tracking_branch())
-                    == f"origin/{worktree_name}"
+                    == f"{default_remote}/{worktree_name}"
+                )
+        elif local_branch_exists and local_branch_has_tracking_branch:
+            if track_differs_from_existing_branch_upstream:
+                assert (
+                    str(repo.active_branch.tracking_branch())
+                    == f"{default_remote}/someothername"
+                )
+            else:
+                assert (
+                    str(repo.active_branch.tracking_branch())
+                    == f"{default_remote}/{worktree_name}"
                 )
         else:
             assert repo.active_branch.tracking_branch() is None