`secretsDir` and `secretsMountPoint`: helping with impermanence and accessing secrets after (re)boot, maybe?

[fooness]

I just switched from agenix to sops-nix, hoping it would solve some problems I experience, but unfortunately sops-nix also comes (for me) with some problems. re: #149

agenix allows setting the secretsDir and secretsMountpoint, for example:

  age = {
    secretsDir = "/persist/secrets/run/agenix";
    secretsMountPoint = "/persist/secrets/run/agenix.d";
  };

If these options were available in sops-nix, for example …

  sops = {
    secretsDir = "/persist/secrets/run/secrets";
    secretsMountPoint = "/persist/secrets/run/secrets.d";
  };

… wouldn’t this help with fixing impermance issues without marking filesystems as neededForBoot, like the following?

  fileSystems = {
    "/persist" = {
      neededForBoot = true;
    };
  };

PS: I’m not even really sure why I need to set that fileSystems = { … }; block for sops-nix to work, as agenix did not need this block, and I somewhat assume that agenix works somewhat similar in regards to when files are accessed, so if agenix was able to access the necessary files located on my /persist filesystem (which is mounted during boot stage 2, but after /root), then why does sops-nix not work without this block?