No worries. For some time, before fully transitioning to Notmuch as a MUA, I was running Gnus with just Notmuch (using nnir notmuch search backend). So no Dovec

No worries. For some time, before fully transitioning to Notmuch as a MUA, I was running Gnus with just Notmuch (using nnir notmuch search backend). So no Dovecot or Sieve. A pure Maildir. I'm not sure whether you'd loose any feature like this, I don't think I did. But perhaps it's much simpler and quicker to switch to Notmuch for Emacs.