Hello, I was wondering if there was any support for the MMC5's ExRAM, either the smaller (8x8) attribute grid that it enables or the ability to select individual banks for each tile. Failing that, is there a way to at least disable the attribute grid so that I can view my graphics how the MMC5 will render them? If not, this would be a very valuable feature for me!

Hi! 8x8 attributes and banked tiles are planned for (wether mmc5, rainbow mapper, or anything else), but it may take a long while. 
I'm struggling to find the time/finances to do significant features at this time, so i might have to take the financing of version 4.0 to kickstarter. I'm working it out, so we'll see!