as I'm the only one working on BTT, my system for commits is pretty uncommon (and would never work in a team) - but has worked beautifully for me. However it really doesn't allow to extract anything useful for release notes.
Basically every build automatically creates a commit where the message is auto-generated based on the changed files and functions. That way I can always go back to any state, but obviously it's not usable for anything else 
However maybe one good idea, I could create a thread here that collects the alpha changes: