For best pool compatibility and reliability I would purchase some of the fan-bypass chips mentioned by several members and leave the firmware stock.
For now you could indeed try leaving the fans connected and hang them out of the oil- however, if they're already burnt it might be an issue. It sounds like something you'll have to experiment with. I wouldn't get any hacked firmware to begin with but so far there aren't very many reliable ways to bypass the fans other than a hardware solution. Hopefully you find a way to make it work.