Expanded palette hack

inserting an "STA $1A" (or STX?) at C1_3E2B will let us zap 4 instructions of the new code.  we can do something similar with Y and $1C, but we'll need an "STZ $1D", so we're saving 2 bytes and negligible cycles at most.  it's a bit odd to relocate the $1A store but not the $1C, yet if speed is paramount...

The way you described this, it sounds like this optimization would be beneficial even if the palette hack isn't in place.
Am I understanding you correctly? This reduces the processing time any time a byte needs to have its bits reversed?