This is an interesting motivation for the project... I kind of get it, but, have you looked at fnox[0][1]? Curious how you'd compare/contrast goals with that if so, I think I prefer that as its not coupled to a single encryption tool (age) but supports age as well as multiple cloud or local options behind one unified interface... I think it can even mix multiple stores together? but I may be missing something/didn't read thoroughly yet...maybe there's a reason fnox doesn't work as well with Nix? fnox was discussed here previously[2]
[0]https://github.com/jdx/mise/discussions/6779 [1]https://github.com/jdx/fnox [2]https://news.ycombinator.com/item?id=45722931