A couple of questions about using NVIDIA as RandR output provider with the NVIDIA 450.51 beta driver

So far, the results weren’t really usable
https://forums.developer.nvidia.com/t/450-51-reverse-prime-issues/129524/18
In general, Bumblebee and any kind of PRIME are mutual exclusives, you can only use one of them.
If the output sink feature will be a full replacement depends on your expectations. So far, much more data has to be collected.