My specific use case concerns the "All Mail" folder exposed by Gmail over IMAP. I keep the folder permanently visible so I can search it when I need to, but I'm tired of pressing c (gnus-group-catchup-current) every time it gets new mail.
I looked for a relevant group parameter in the manual, but couldn't find it.
I can write an appropriate function and either add it to gnus-group-update-group-hook or set the gnus-group-update-group-function, but first I thought I'd ask.
Is there a more idiomatic way?