Greetings.

I would like to be able to truncate the commit history of the master branch (or, ideally, arbitrarily rewrite history).

At the moment I manually prune commit history via this guide which boils down to:
1. Squash commits of the master branch and git annex forget --drop-dead --force;
2. Force-push changes to the master and git-annex branches for each repository;
3. Delete sync/... branches in each repository.

The problem is that rewriting history this way requires all of them to be online at the same time.

Can this be done in an asynchronous manner?

Thanks.