You can't checkout if you have tracked changes. If you mean you lose untracked changes, then a) it's unsolvable in the general case unless we all start doing ou

You can't checkout if you have tracked changes. If you mean you lose untracked changes, then a) it's unsolvable in the general case unless we all start doing out-of-source builds, so don't have to worry about build artefacts and b) it's already solved by git-worktree, so if you haven't RTFM, adding new features won't matter anyway.