My main usage of Nix is on non-NixOS machines, and I use Home Manager, and while it has a similar problem, just searching the options in the packages it provide

My main usage of Nix is on non-NixOS machines, and I use Home Manager, and while it has a similar problem, just searching the options in the packages it provides configuration for is a smaller issue. Not sure if this helps you at all or not, it really depends on your usage of Nix, but for managing user configuration I do recommend Home Manager.