Generic NVMe is only supported by macOS after 10.12 for 4KB blades and 10.13 for 512B blades - for Apple made blades, the support start is with 10.10.2.
OpenCore can't help since the earlier macOS itself cant work or talk the proctocol of NVMe, non-existant at macOS level.
You can read the whole story on the first post of the sticky thread:
This is a general info thread for blade SSDs that can be used in the Mac Pro. This is a WikiPost so anyone with the proper credentials may edit it. NVMe SSDs can be used as a boot drive in the MP5,1 and MP6,1 with the latest firmware installed (beginning with version 140.0.0.0.0 for MP5,1 and...