[Tyhm]

Ungh.

Arrays? Yes it'll work, yes it'll be easy to script, but Oi. Arrays online are nightmarish. Until recently it was nearly impossible to tell if they'd been initialized, and I think it recently changed from filling with 0s on redefinition to preserving the old data. Very irritating.

Plus there's the problem of what if you're trying to do this in an overburdened system NPC. That makes it even uglier.

Advantages to my implimentation:
Does not require an additional command
Backwards compatible - changeimgvis 0 is going to be exactly the same
No display slowdown. It already checks layer before deciding to display above or below - what would it matter if it's a floating point or integer? The differencec in comparison time is negligible, if there's a difference at all.