Touko, is this an edge case scenario issue?
Ryphecha's always strived for accuracy for her emulation, as far back as I can remember. She even added different audio implementation for emulation depending on chip revisions, etc (she's done a lot with accurately emulating the audio chip). And a bunch of other stuff too. I would at least ask. Also, I have an SGX so I might be able to confirm some test stuffs. It might be better to talk with her on the mednafen IRC channel.
I wanted to see if she could implement that hacked mode for 8 pixel tall sprite cells, but since I haven't made anything with it.. I haven't asked. One of these days, though.