After hundreds of milliamps released the VOC smoke of heck, it turns out, using optoisolators as gate drivers is a bad idea, and I wasted $50 of optoisolators and a board revision.

There's a reason I haven't released schematics yet, it would be like encouraging you to hurt yourself.

I'm going to revise this with the Microchip ATA6844 driver, and may switch to the Teensy dev environment, after an enlightening chat with Kai Yin. Thanks for stopping me from doing something dumb.