I haven't seen an alley oop fs 270 to fs nose slide. I feel like I can do it on on a 4" curb and slide 2" if I tried all day. I'm sure someone good could do a legit one.
I dont think I've seen big spin nose blunt slides. Maybe I saw Gallant do one bs but from behind the ledge. Preferably they would be done in the middle of the ledge instead of from behind. Either fs or bs would be outfuckingrageous, but I think with all these massive pop monsters lurking around these days, someone would get it done if they felt like it.