Git already has a mechanism to prefix author initials... remotes. If you need to segment branches by author, I would humbly submit that you ought to be using forks.
This assumes you're using github. If you're bound to a central repository in an enterprise scenario, there's generally only 1 repo per project and forks aren't a thing.
Note: They should be a thing, but most enterprises also don't "get" source control, of any kind. Using author initials to supplement a gui is almost as bad an idea as using the commit title line to track project management information.
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