So, I have seen this issue on both R740 and R750. I understand the reason but can't find a work around. I'm using a supermicro dual nvme adapter and bifurcating the pci slot to x4. The dell bios will kick back that there's a pcie link training issue and essentially shit the bed. Anyone have thoughts on how to handle or bypass the issue? The drives will not be bootable, they just need to be exposed to the OS.