Firmware and Mac Pro 5,1 and NVME drives with OCLP

I have a Mac Pro 5,1 in which I have installed Sequoia straight from High Sierra with OCLP. I've recently bought an NVME drive. When I look at the firmware version it says 999.999.999.999 which I presume is a fake version supplied from OCLP. Can I get full speed on the NVME drives with OCLP or do I need to install Mohave to get the 144.0.0.0 firmware installed?