can you do corks? f it is basically necessary as a d spin is just a way-over-cork from my understanding.
when i set for d i just roll off the lip as if i was going for cork, but drop my shoulder more and almost reach back for the lip so that I go right upside down. From there the rest is very similar to a cork in which you dont go inverted, look for the landing and roll out the last bitunder your shoulder.
as for injury stats, i cant emphasize the necessity of being able to do corks enough. you cant just jump into something this off axis and inverted right off the bat unless you know other less gnar offaxis spins already.
Gave up tech nines for big lines...
100k M4, i 5p33xz 1337