The walljump asm featured in KLDC 2021's entry #45 (Not Cataclysm).
This walljump asm mimics the physics of the TAS-only walljumps that are frequently seen in pit hacks but makes them consistently performable for a human player. To be specific: Mario always clips the wall if he hits it with 29 or more horizontal speed while moving downwards and the window for the jump input has been increased from 1 to 5 frames.
If you decide to use this, you should use a patch that disables the real vanilla walljumps as the player may get confused and frustrated otherwise.
Rejecting for a few reasons. First thing that I noticed was its lack of SA-1 compatibility. This isn't the worst thing to leave out (and if this were the only problem I would probably convert it myself), but given there are other issues I recommend you make compatible. Secondly, the sound effects when jumping off the wall don't seem to work properly. I get no SFX when normal jumping until landing on the ground, but spinning seems to work fine. Last thing I'd mention is that it doesn't work with layer 2 from my testing. Checking on a vanilla rom, I was able to clip on both layer 1 and 2 with the consistency you'd expect, but this code only seems to give the leniency on layer 1. Hopefully these aren't too difficult to fix, but once these are taken care of it should be good to go.