Using agenix for docspell secrets

I want to move from the docker deployment to the Nix-deployment. I'm handling my secrets in NixOs with [ragenix](https://github.com/yaxitech/ragenix). But I'm having a hard time to figure out how to use ragenix with the Nix modules of docspell. Is that even possible, currently?
Ragenix and agenix are file based, that's why the options which take the secrets, have to support file based secret handling. I'm guessing I could deploy a config file for docspell and replace the secrets with the trick mentioned at the bottom of https://nixos.wiki/wiki/Agenix. But it would be nice if this hack could be avoided. Is there a better way to do this?

Start by reviewing docspell’s Nix modules and the agenix/ragenix file-based secret model described in the issue. Compare the module options that currently accept secret values with the linked NixOS wiki approach. Done means documenting whether file-based secrets are supported and, if not, defining the required module behavior.

Written by the indexing model from the issue text.