Firefox has a wrapper with rich features. I can add many configs with a overlay. But it’s not very easy to discover those wrapper options without reading the code and it’s not well-documented. A nixos module for firefox is a natural idea to provide a better UX.
There is already a module for chromium and there is a PR for firefox module. Unfortunately it only got a comment that home-manager should be used instead. Home-manager is good and it has a good firefox module. However I’m a NixOS user instead of a HmOS user. There is a function in home-manager is not s solid reason to block a function in NixOS. As the only user on my NixOS, I don’t want to intruduce a third-party tool to manager my system which is not even a NixOS module. (I’d be happy to use home-manager if it’s integrated into NixOS.)
Maybe a Firefox module in NixOS has less features than the one in home-manager, it can serve as a good abstract and UI of the wrapper.