EnvKey[1] might be interesting to you (disclaimer - I'm the founder). It's similar in principle to the homegrown system you've created, but has had a lot of time put into smoothing out the ux. It gives you a single place to manage configuration/secrets for all your projects.

It uses OpenPGP.js (maintained by ProtonMail) and golang's crypto/x/openpgp instead of gpg.

1 - https://www.envkey.com