Does this actually impact the remote IMAP -> Stalwart route?
That said, getting timely notifications is definitely an important point!
ImapGoose is on my radar to replace mbsync and imapnotify in my setup, but I think it's IMAP <-> maildir only, which makes sense for the intended use case of local mail
and it's excellent, I have run it since the HN post. Replaced all the old ways for regular IMAP. Gmail still using lieer.