as I understood, in case of these SSD installing won't work, you have to get working system on external USB3 drive, and then clone it. And while booting from ext drive and enabling NVme will still cause panics if you use native kexts. I am still waiting to try dsgvsn files with my installation to see if it will solve it (currently my laptop is not with me).
I don't know about spoofing 970 Evo - what I know that no one has problems with it, so better just change to this drive if we'll not see any improvement.
I've seen on some Chinese forums that 10.14 fixed PM981, but have no idea if it's not fake info