I've done it into a foam pit on skates. Shit was so easy to just whip around. I don't see why anyone wouldn't be able to do it. That one Yasutoko kid was rippin legit doubles in the pipe at one point.
I think it's more possible to do a kangaroo flip onto a rail with inlines than it is to do a kangaroo flip onto a tranny. It's just the way the sport is, these guys spin more onto rails than they do off of drops. Or at least that's what it seems.