Hello!

I just tried to run a plasma wayland session with nvidia-370 drivers and nvidia-prime for optimus support. After login, the display stays dark

Any ideas to get plasma wayland working on optimus systems?

Have you tried logging back into the X session?

I tried Wayland on my own Vanilla System76 system and it completely borked the laptop. Had to reinstall KDE Neon. Playing with Wayland is like playing with a box of matches in a barrel of gasoline. You might live. You might not. If you're already getting a black screen of death, and if you can still log back into X11, I'd cut my losses if I were you. You'll find similar warnings elsewhere... You've been warned.