I would like this as well. Nix is a low effort but high reward for Proton ecosystem. I could install Proton Pass CLI on my machines declaratively and use Proton secure secret manager. There are most likely unofficial packages, but that is really not ideal since Proton Pass is so critical.

Nix is one of the most secure ways to distribute your app. Please create a Nix flake with linux and macOS support and have it maintained in the app's repo that users can add to their Nix configs.

This would provide the best end to end security, simplify updates and it's a very low effort feature for potentially a lot of new users.