What currently exists appears to be sufficient, but it is not nearly as good as it could be. I have seen other posts that request these ideas before, and I would like to amalgamate them here.

Lookup public keys through external services, such as keys.openpgp.org

Safety indicator to ensure the e-mail you are sending is encrypted when sending to non protonmail contacts

Allowing encryption to be managed with an external application through proton bridge, (including a confirmation dialog on proton bridge to prevent accidentally sending unencrypted e-mail)

Any of the above ideas would enhance the experience that is currently available, at the moment it feels like Proton is uninterested in fully supporting exchanging mail with people outside of their ecosystem. I would like to believe that isn't true, as there is an established group of people who already use PGP who have no reason to use any of Proton's services. I do not aim to criticize, Proton's mission is admirable, but it needs to be recognized that the established group of FOSS enthusiasts will never be a part of the target demographic. However, that does not mean said demographic will never be interested in interacting with this established group.

I believe it is very important to support this use case in full, as a first line feature of the platform. While support exists in a limited fashion, at the time of writing, it is less user friendly to add an external public key and send an encrypted e-mail to that contact than it is to set up Proton Bridge and setup an external e-mail client to encrypt e-mail. The only issue is that that does not work, and Proton will corrupt the email when sent in that fashion.

Please please please continue to enhance support here, I purchased a year long subscription believing that Proton would sufficiently support my use case, and I am currently disappointed with it.