KubeRoot

I got the impression that the PolyMC situation was quite different, with that developer masking it and doing a minority of the work, but after one change made by the rest of the developers they snapped, used their control over the repository to remove the rest of the maintainers and take sole control over the repository.

I was aware of some shenanigans and hostility from PolyMC and never used it, but I got the impression there were no major outward signs before that happened?

I’m not sure if this is what you mean, but I do want to clarify - the drivers in the repository are still proprietary drivers from Nvidia, just tested and packaged by the distribution maintainers, dkms is just some magic that lets them work with arbitrary kernels with minimal compilation. Unless you’re using nouveau, which I don’t think is ready for most uses.

I’d definitely recommend against using drivers downloaded from a website, on general principles.

custom kernels don’t work with the drivers from apt

Check if there’s a dkms version - I know that’s the way it’s set up on Arch, if using a non-standard kernel you install the kernel headers, and dkms lets you build just the module for your kernel.