Earlier quoted context omitted.
Why is a keyring important to you? Would "fetch a short-lived age public key" serve your use case? If so, then an age plugin that build atop the AuxData feature in my Fediverse Public Key Directory spec might be a solution. https://github.com/fedi-e2ee/public-key-directory-specificat... But either way, you shouldn't have long-lived public keys used for confidentiality. It's a bad design to do that.
We need a keyring at a company. Because there's no other media for communicating, where you reach management and technical people in companies as well. And we have massive issues due to the fact that the ongoing-decrying of "shut everything off" and the following non-improvement-without-an-alternative because we have to talk with people of other organizations (and every organization runs their own mailserver) and the…
Look closely at the UX I'm proposing in https://github.com/fedi-e2ee/pkd-client-php?tab=readme-ov-fi...
Tell me why this won't work for your company.