So poss, plus IF you tag the ledge, that ledge kinda swerves you into posiiton, if you try the one done in Fracture, by Iskanderr you'll see that alot of the time you dont have to land at a perfect 90 degree, in fact alot of the time the ledge kinda does the straitening and grinding for you. You simply have to tag the ledge without to much downward momentum and have close to the right angle, but its definitely one of those stunts that IF you get to the ledgegrind, you damn well better hope it doesent stick or bail you for some reason.
Possible.