Overlap inches is set in the work area advanced settings.
(So in each work area)
As for ideal overlap, I’d prefer no overlap, as that would provide the fastest mow possible.
I don’t think that is realistic with the way it is working today. I’m sure over time Yarbo will improve the navigation and this will become more accurate/reliable.
As far as cutting at a different angle goes, right below overlap is Route Rotation Degree.
(It is a Parallel route pattern only setting)
Here is the explanation from the app.
It automatically adjusts the angle of the mow, which is what I believe the goal is behind your question.