Sometime ago I abandoned the practice of insulating Rx's aginst crash damage switching instead to industrial velcro CA'ed to the Rx bottoms and the floor or sides of the airframe.

vibration isolation proved a none issue and surprisingly crash damage did not notibly change.

Now having gone all 2.4 for some time and given the apparent bit of extra sensitivity to heat I never wrap rx's at all anymore. And this comes with the added benefit of much easier packaging of the components especially in the smaller airframes.

John