Ihave seen a member try to fly a heavy trainer with a .40 and a 10X8 Top Flite prop. A 10X8 is bad enough but a Top Flite prop has a much higher loading than most. Ibarely flew. He simply switched back to a 10X6 Master Airscrew black and it flew correctly. Still it was a bit under powered for the weight of the plane.
2 stroke glow engines are like any other engine and respond to mods just fine.