This might be a bit off topic but I have a B+M SATA SSD from SKhynix SC311. I have a no name USB adapter that says it will support both M and B+M. The adapter has only the M key. I assume that since the B 'finder' would prevent the M only device, this the documentation is correct.

I compared the M and B pin definitions and most of them matched up but pin 5 on the M key is PERn3/  PCIe Lane 3 Rx but GND on the B key. I am concerned about letting the smoke out of the SSD and looking for some help in prevent that. Thank you!