FWIW, I'm using Sway with Nvidia right now and it's as smooth as silk with no white flashes. The wlroots-eglstreams package is key to avoiding the artifacts. The only issue I have is Zoom - but that's hopefully being solved by the Zoom guys themselves. Arch:
lib32-nvidia-utils 510.54-1 lib32-opencl-nvidia 510.54-1 nvidia 510.54-7 nvidia-utils 510.54-1 wlroots-eglstreams-git 0.16.0.r5388.0558b203-1 sway-git r6897.1e79088a-1
Good luck!