He fixes now tens of power inverters (surface mount) from solar farms in EU, damaged by lightning.
He can buy all boards requiring repair or the whole miners, repair them in advance to offer prompt replacement on board 4 board basis.
Not sure if it makes sense to pay 100 euro or more for repair if the price of new miners falls every few months by half.
Sounds interesting. Just be aware that the chips are 0.4mm pitch MLFs with glued on heatsinks and no well done self-centering pads.
If the repairer only has experience in power devices hot air / IR reflow, I would suspect he is going to struggle to get the accuracy and paste requirements down for these chips.
Good luck though!