i can't time the piston by counting because every time i count the timing is different, so my method was to let go and re-hold down as the piston brushes up against sonic, and depending on how early/late i was, adjust how long i crouch before holding right. once i jump i hold left, wait a bit, full jump, hold right for a bit then roll. as soon as the screen shifts to the left i mash A and tap left lightly. doing it this early is dangerous but necessary for a 24, you can actually wait a bit longer and you will eventually fall consistently.