I have decided not to put any more weight in the tail of mine, since it already pitches up when inverted. Mine does the best inverted flat spin on low to no power of anything I've owned or flown. When applying power to try to speed it up and stop the decent, the right stick needs to be jogled, or feathered, or it will tumble or roll out. I enjoy flying this thing in knife edge all over the sky, big figure eights etc.
DKjens