yes, very interested in the emails you can't import. I don't work for ProtonMail btw, just have quite bit of experience with smtp and email. Just curious from a tech perspective what kind of email you are having trouble importing.
Big plus is that if you complain about this to their support things actually seem to get fixed? That was kind of a shocker, I'd suggest sending them a note if you have issues. Though this particular IMAP transfer between accounts has worked between my other email accounts (exchange and some linux server long ago) and gmail since I first tried it so it's a little sad. But a smaller team I guess? But paying for it so...
Mixed feelings for sure.