I want to move tfvc to tfs git. I am going to use git tfs tool https://github.com/git-tfs/git-tfs/blob/master/doc/usecases/migrate_tfs_to_git.md
After I push to origin there will be some more checkinswto tfvc, therefore I want to re-migrate. Is it possible, or this only supports migrating to a empty repository?
No, you can't re-migrate in an existing repository. You need ans empty folder.
But there is better. You simply don't have to re-migrate!
If you don't clean the necessary git-tfs metadata ( described in https://github.com/git-tfs/git-tfs/blob/master/doc/usecases/migrate_tfs_to_git.md#clean-commits-optional ) that will prevent git-tfs to work, you can just fetch the new changes and push them to the git repository. That's the normal behavior of git-tfs.
Just do:
git tfs pull
git push YOUR_GIT_REMOTE
