That’s superfluous: nixpkgs/nixos/modules/hardware/video/nvidia.nix at 9b5ac7ad45298d58640540d0323ca217f32a6762 · NixOS/nixpkgs · GitHub
As are all the boot.kernelModules (those are the defaults) and boot.kernelParams (since you set hardware.nvidia.modesetting.enable).
I’m suspicious of the other extraModProbeConfig options, too. Most of them look useless. vblank_sem_control=0 might do something, but it will likely cause other issues that are less immediately apparent, and if it does fix anything the original issue will eventually be solved with a driver update, at which point you now have this useless, potentially problematic option set, so at the very least you should add a TODO comment to remove it.
I’d really suggest just removing all those boot options unless you actually know what they do or have asserted that a particular one fixes an issue you’ve run into by isolating all other variables.
In addition:
Nvidia recommend you set this to true, since your GPU supports it.
You’re also duplicating a lot of default options in the hardware.nvidia module, check search.nixos.org to see option defaults; it’s usually best to leave defaults at the default, in case upstream changes them for a reason - then you don’t need to figure out that reason as well.
But yes, the powermanagement daemon is important to make sleep work, I would suspect that missing that setting is what is causing issues for a lot of people here, as pointed out much further up in the thread 