Age is a file encryption utility that is more robust and easier to audit than similar functionality in GPG. Reputable people like Str4d and Matthew Green are involved. A rist implementation is in the works. Str4d is working on a GUI, has already packaged it for Debian and also has a Rust implementation. A container mounting fucntionality is planned. Let me know if it interests you to include it and I will open a phab ticket.
https://docs.google.com/document/d/11yHom20CrsuX8KQJXBBw04s80Unjv8zCg_A7sPAX_9Y/mobilebasic