I don't know, it also happens in the original, for some reason you can press A on the 1st controller to start the spinjump and hold A ob the 2nd one to make the spinjump go high. This applies to every usage of the A button.
It's ASMT, not much there is to say about it. It's no secret that this hack hasn't aged very well at all. I kind of wished you had made some edits to make this bearable to play toolless (adding more midpoints to certain levels would've sufficed), but I can see why you'd want to preserve the game's original state.
Glad you submitted this. We can always use more fixed accurate hacks.
Can confirm that permission was given for this.
For the record, updates for hacks with the "fixme" tag typically don't require permission from the hack author as long as they contain only the fixes necessary to make the hack work on accurate emulators and hardware. This update contains quite a few changes in addition to its accuracy updates, thus it required permission to submit.