What ever amount of overhang is present, it can’t be wrong if “installed as per manufacturer’s written installation instructions”, usually located on every bundle of shingles these days, (and online). Actually identifying the shingle manufacturer can be a challenge of course, if not already known.
The point is this, in litigation work, when ever there is a complaint about the roof installation, or re-roofing installation, among what ever else might be wrong and driving the complaint, this edge detail question gets tossed into the ring also, as one more arguement why the whole roof needs to come back off and be done all over again.
Personally, I think that even with the heavier shingle weights, and being in a coastal wind zone with a 6 nail spec, I would flag any installation that exceeds one inch, at either the eave edge or the rake edge. BUT more folks get in trouble for having no overhang beyond the edge metal than having too much.