Kudos and the Hard Line

[Jackalope]

Is it possible to automatically add a user to a group based on post count? Then you could "Selectively exclude user groups from post merging" without anyone having to seek to become part of the group.

Yes it is.

I have some questions on how it works (e.g. whether the change is applied retroactively to users meeting the criteria), but I'll investigate.

OK, so the group has been enabled and the auto-promotion set up.  Check this page (if you care), you should be added to the "Established Members" group.  The current criteria is 30 days and 30 posts to align with the 30/30 rule.   Staff is discussing where the threshold should be and that's the current favorite.

I'll disable the auto post merge for established members this weekend if there's no objection amongst the staff.