Aglar, I'm interested to know how you find these boundaries for the subpixels.
I didn't think y-subpixels mattered for this trick so I went ahead and tried to come up with something using TeeNTee's latest S1 TAS (14:25.23)
Just holding left worked for no frames at all in his TAS (Y = 943:250) and instead tried to see what ranges I could get out of the release-method TNT used. My results were (all frame data is in 38XY format):
LEGEND
*******************
Inputs: left, release, left
------------------------
frame of first input
------------------------
frame of release
range where holding left again allow you to clear the level
*******************
------------------------
left at 46
------------------------
release at 48
nothing
release at 49
55-65+
release at 50
58-65+
release at 51
nothing
------------------------
Left at 47
------------------------
release at 49
nothing
release at 50
leniency for left: 55-65+
release at 51
leniency for left: 58-70
release at 52
nothing
------------------------
------------------------
Left at 48
------------------------
release at 50
nothing
release at 51
55-65+
release at 52
59-65+
release at 53
nothing
------------------------
------------------------
Left at 49
------------------------
release at 51
nothing
release at 52
59-65+
release at 53
59-65+
release at 54
nothing
------------------------
------------------------
Left at 50
------------------------
release at 52
nothing
release at 53
57-65+
release at 54
59-65+
release at 55
nothing
------------------------
(the same pattern, wait 3-4 frames then having a big window for left again seems to be reasonable to assume for a number of frames ahead but 4 frames is plenty for consistency so I do not bother checking them)
x-position at random wraps 8231:0 always
This seem to work well for arbitrary y-subpixels but again, I don't have a method of finding the ranges other than randomly jumping on the wall before wrapping and hoping I get a weird value so it's hard to tell when I'm playing on console if my inputs are bad or how much of an effect subpixels give.
It's also 4 am and I don't feel like playing Sonic right now.