yea i theres a bmx rider, i forget his name, but he does this thing where he starts in a front flip rotation and does a 180 at the same time, and then goes into pretty much a switch flat spin 5. Ive gotten close to doing this coming off a flybed jumping to pads. I feel like it would definitely be possible, and would be a really dope trick to do off a cliff. Im not sure if thats what your mean by a forward flat spin though. I also want to see a bio 3, thats another thing ive seen some people almost getting on tramps.
And theres still room to progress simply with grabs. For example, correct me if im wrong, but im pretty sure no one at this point has incorporated lead japans, or double/2 handed blunts into dubs. And speaking of two handed blunts, i really want to see someone get an uncrossed 2 handed blunt, so theyre grabbing both of their tails on one side of their body, in something like a cork 9