Hey there. You didn't mention how strong your straight edge is. Can you get into a solid straight edge via other entries, such as from an inverted crucifix, from a handspring, or even from an elbow grip ayesha? If not, I'd suggest working on that first, since then your body will know what position and balance it's trying to achieve already before you add the momentum component. For example from an inverted crucifix, you could go into a aplit grip ayesha into a straight edge facing the pole, and then rotate that 90 degrees to be side on to the pole. Feeling confident in that position will really help you commit to the momentum of the cartwheel knowing exactly where you are going at the top of the move.
I'm injured at the moment, so I can't check my actual body positioning, but I seem to remember the key to positioning for me was tucking my butt in and squeezing it and pointing my toes to the ceiling, so get everything is in a stacked, straight line. I think it's similar to the position you use to do balanced freestanding headstands and shoulder stands. Also, going into it, make sure you are really committing with your head. If it doesn't go completely upside down, it throws off the rest of the balance completely. Cartwheel is one of my favorite moves, but I find I'm still nervous about doing it on my weak side, and being nervous means I don't completely commit my head. Then my body can't get into the right position and it's just not going to happen. Just one of the many things I'll be working on once my shoulder finally heals. Good luck! Cartwheel is so much fun and it sounds like you are really close.
