With Simplelogin integration Proton does PGP encryption because effectively all emails are forwarded by a simplelogin address. I have just tested to be sure, and I can confirm it is the case. I agree though that this only protects “my side”, which is why I said that it doesn’t provide all the PGP features.

Publishing your PGP public key next to your email doesn’t require “wasting a domain” or anything like that

It does if I don’t have any key that I use for emails. My key(s) is bound to the Proton account with the other domains I use, so for this domain I would need to either add it (back) to Proton (easier option, but “wastes” a domain) or just generate and manage a key myself, that I can then even add manually to Proton, but I didn’t bother doing this just yet. I am not going to use any other public key I have because I wanted specifically to keep this domain separated from my identity.

I just thought it was amusing that you didn’t seem to actually follow your own advice.

FWIW, I do follow the described setup for everything personal, which is what matters to me. As I said, ~1/2 months ago I did have my PGP key because I enrolled the domain into Proton, which if anything is a testament to how annoying it is having to manage keys myself (which I already do for signing commits etc.). Maybe I will spend some time to polish the setup, eventually.