So I have a Model 3 with the Bluehead 582. She seems to have endless
power - at a cruise RPM I can easily hit 90mph indicated, or more with
some extra throttle (lightly loaded)

We all want more speed out of our planes, so if it's calm air what
truely is a SAFE/SMART level flight 'cruise' speed for a model 3? in other words what would be the failure if you're going too fast, the fabric adhesion to the ribs?

Thanks for the insight...
~Wild