What I would love to see is some kind of indication that you are overspeeding the airframe.I think I notice a flutter effect where plane bobs up and down(seems the Nieuport series has this but again it could be just imagination).If this could be magnified and starts when you are nearing the speed where damage occurs it would be simply marvelous!Heck it could also be used for when nearing stall speed.

EDIT...oh and engine damage from overspeed forcing you to manage throttle setting in dives.