Just realised that if you want to dip into the madness of Conventional Commits, you should use git trailers for the metadata. Don’t clutter up that first line, but add the tags at the end if you must.
Why don’t we want to clutter that first line? Why the 50 character limit when monitors these days allow greater resolutions than the old 80 character width limit?
One word. Scannability. With git log —pretty=oneline I want a vertical list of meaningful summaries I can scan down without too much lateral eye movement. Try doing that with 140+ characters! 50 wide seems about right.