I have bad experience using M2 adapters - tried to power them and it basically smoked and burnt the 4-pin adapter that was provided - that 4-pin molex adapter is of very low quality.
It wasn't by chance this model was it?
https://minerparts.com/product/pcie-4x-to-ngff-m-2-adapter-with-4-pin-power-cable/I got a couple of those on order to use with Asus PRIME Z270-A (7 PCIe slots) boards, so that I can run 8x 1080Tis per rig.
If the issue is just the 4-pin adapter provided, perhaps I can custom solder (been swinging an iron for 20+ years) my own cable (each rig is going to be powered by a Delta 2400W PSU). So I'd take one of the 32 6 pin to 6+2 pin cables that comes with the REV2-Ultimate kits, and replace the 6+2 pin connector with a 4 pin floppy connector, no?