I think the original post is still a good request. Actually, on a share familly home computer, you must keep all user connected to bridge to be able to send or receive email from IMAP/SMTP client.

There is no problem if the account connected is only for one email address, but if you use alias or custom domain with multiple inbox, you do not want all those mailboxes available to the IMAP/SMTP client. Actually, someone can add an IMAP account to access those mailboxes without authorization because one of the mailbox need to be accessible anytime and so the proton account is always connected to bridge . There should be password protection for each alias or account before accessing IMAP/SMTP connection information