I’m working on the same collection. I’ve tried it for a few times (mostly because like you said, it takes a while for the skills to unlock, and couldn’t pull off all the moves). But it worked for me and got it after five times trying.
However, I’m having trouble at Timberline Falls for the Sipedon Performance. The dive is WAY TOO SHORT to pull off a flip-spin-flip at all. Tried it for 20 times already and still can’t pull it off at all. Did you manage to get it done?
Edit: Ignore my idiocy, apparently I was at the wrong diving spot. I got the Sipedon Performance already.