what eventually got it reading anything at all was to enter Script:ReadMem(B9). but now i'm running into the issues of:
1. setting z1 not having any effect on object position at all.
2. the fact that when y1 is set to read from B9, it keeps spitting out numbers that are inconsistent with the information in the linked FCEUX lua repo (constantly changes between higher values than it should and zero even when the player is standing. gonna investigate more in FCEUX myself just to see if there's something i'm missing though. because applying the value from B9 to the shape.Offset.Z of the player sprite, it flickers between way out into the field and back to where it was.
Edit: okay, i solved most of that. the trouble is now i can't rely on memory addresses because if i want it to apply to enemies there's too many memory addresses i'd have to look up per the fact that there's multiple enemies. and also items. i'll post my current 3dn in the WIP section but unless you can get certain states without memory address reliance, i think i'm probably gonna only poke at it every so often.