@justiceisblind for the chest to wall Hs, the closer to the wall ur hands are the harder it is (keeping hollow body to avoid resting too much on the wall tho) but u can try L handstands against the wall which is way easier, the one that Gabo Saturno demonstrates in his beginner handstand follow...
@mark1 well it's usually bothersome to not get up from the seat in a crowded gym (ofc it's ok if the gym has plenty of space or is pretty empty), as someone will probably want to use the machine too
but still, the guy is a dumbass
@carina2111 steven low wrote an article on that, its definitely useful information
http://stevenlow.org/how-to-program-for-advanced-isometric-movements-after-a-plateau/