You still should not use it; or at the very least be aware thet any update may irreversibly break stuff. Because the driver is out-of-tree, it cannot update in lockstep with the kernel, so it happens pretty frequently that the kernel updates and for a few weeks to a month or two the nvidia driver fails to build. Since nixpkgs doesn’t package EOL kernels, this can leave you stuck.
Sticking to LTS kernels means that you don’t run into this problem, since nvidia can target LTS releases, and nixpkgs keeps them around until they reach EOL. Dropping the _latest really will improve your experience a lot, a large part of why people struggle with nvidia is probably just that.