I think I am about half way through this project, and would love some help completing the task.
Adding a secondary group via SQL using an email list works fine like this:
UPDATE xf_user SET secondary_group_ids = '6' WHERE email IN ('email1@gmail','email2@gmail');
Unintended behavior 2: Once secondary groups are set using this method, adding an upgrade package which adds these users to a secondary group no longer works. When upgraded, they are not added to the secondary group associated with the upgrade.
At the same time, I would like to add an upgrade package for the list of users. I imagine the SQL would be similar to Part 1, but I don't know the proper syntax. I think I would need to know the term for the upgrade package equivalent of "secondary_group_ids". Again, its important no other upgrades are removed.