Guess I set GPU voltages too low. Or whatever. Anyway now Win10 will not start. What are my options?

I have a 6x Vega rig on Onda D1800. Access to the rig is difficult so the less I physically have to tamper with it, the better. Would flicking the secondary bios switch make Windows recognise it as a new GPU (and generate a new reg entry)?

Or will I have to reinstall Win10?