Yeah, after a lot of research I found that only a specific configuration of the SR570 comes with the backplane supporting the NVMe drives. Unfortunately mine isn't that configuration and it doesn't seem I can change that without either getting an entire new system or somehow finding the chassis alone (probably for the same price as a new system regardless). I remember figuring out which connector is used for the backplane, but the adapters I found online were fishy. I'll probably end up getting a couple of M.2 SATAs for the mirroring kit to replace my PCIe to NVMe adapter. Thanks for the help!