I often remove the case, mostly for the tiny noses on some foamies and DLG-planes. Not much space...
If you want to wrap your RX in any kind of foam take care! Some foam and bubblewrap-plastics are anti-static, this can cause short-circuits to your RX. Especially some of the black bubblewrap but also pink/red types.
Do as exeter_acres says, buy a micro-RX. I`m very pleased with my Penta5`s, just 4 gram and 5 channels...