impermanence VS raspi-overlayroot

I would not call these projects unbelievable, but they are neat.

- Opt-in state: https://github.com/nix-community/impermanence and https://grahamc.com/blog/erase-your-darlings/

That way will work - I use the impermanence module which works similarly but allows to hide mounts.

This is indeed a blind spot. Thanks for pointing that out! Silverblue -to my knowledge- doesn't do a lot to address this. Though, 3rd-party tools like Home Manager and the suite of applications developed by the folks over at uBlue might be able to limit this to a minimum. Though I'm not sure if it surpasses NixOS in this regard; for the uninitiated. Though, to my knowledge, this requires special attention and depends on the specifics of the NixOS system in question.

[3]: https://github.com/nix-community/impermanence

I have recently stumbled upon Impermanence - modules to help you handle persistent state on systems with ephemeral root storage, and the concept seems quite nice.

I haven't used it yet but nix-community/impermanence has a home-manager module that might be useful.

Some files in /etc (like saved networks) will still not be managed by NixOS, if you want to have full control over them use Impermanence

{ imports = [ (modulesPath + "/installer/scan/not-detected.nix") "${builtins.fetchGit { url = "https://github.com/NixOS/nixos-hardware.git"; }}/system76" "${builtins.fetchGit { url = "https://github.com/nix-community/impermanence.git"; }}/nixos.nix" ];

There is a maintained collection of modules for running this kind of NixOS setup. It's called impermanence.

You could use something like https://github.com/nils-werner/raspi-overlayroot , works really well