This is one of the things I like with NixOS: it's easy enough to add new packages and patch existing ones that stuff like this can either live in the core nixpkgs repo or be managed through some community-supported overlay. (Great example of this is [nixos-hardware](https://github.com/nixos/nixos-hardware) which shares settings and fixes for specific laptop models and the like, or [emacs-overlay](https://github.com/nix-community/emacs-overlay) which has a bunch of extra Emacs-specific stuff that would not belong in the core repo.)