I'm in the middle of my Invader build and decide to see what was posted. Wow, people are having problems! A couple of things come to mind, most have been mentioned. First we have 2 vehicles. First is a rocket during boost. For this the CG needs to be above the CP, where is the CP on a disc? Any weight added for finishing will move the CG aft. It sounds like the invader is marginal at best so any aft movement is BAD BAD BAD, as is any wind. Wind adds angle of attack, angle of attack adds lift, lift cause's a loop under power. The invader has a flat wing, it can generate lift in either direction depending on the angle of attack. Any deviation from zero angle of attack during boost will cause trouble with a marginally stable rocket.

I think I will go with one coat of dope and be done with it.

Second is a glider. For this it needs to be trimmed for best glide speed. Best glide speed is NOT the slowest glide speed. If you get a good glide during a hand toss it will stall after boost. You want a controlled, steep descent during hand tossing. The speed it will glide at after ejection is much higher than hand tossing.

This is of course all a thought exercise for me so far. Hope it helps.

Mark