[Slothie]

just one minor thing with the PCB, I noticed that pin 1 of the opto-isolators isn't all that clearly marked.
Normally I would make pin 1 a square pad, but I seem to have forgotten to on this board.

Pin 1 is indicated by the barely visible silkscreen "dogleg" next to the pin, which is top right on the horizontal row of 9 isolators and bottom right on the vertical row of 4 isolators. (see pic)