I'm thinking of wiring that resistor across the BMS with a normally open push-button switch. So the turn-on procedure will look something like this:
- Hold down precharge push-button for 10ish seconds
- Turn on BMS output switch
- Release precharge button
I'm only slightly worried about running this across the BMS -- but I think the only real failure point is if the normally open button becomes a normally closed button. I'm not sure how terrible of an idea this is.