When I subscribed, despite my long history as a Yahoo group owner, I found the mail options confusing and botched it!
I can only imagine the nightmare that's in store if we can't have the option to go with a simplified plan. Good old KISS is best for older folks.
In my groups, we use subjects, don't need hashtags, and the delete key is fine for unfollowing particular threads.
We need only a choice of three mail options:
All messages as single emails
No Mail except Special Notices
Mark, I appreciate all the sophisticated programming you've worked on, but I beg you to make it possible for group owners to opt-in to a simplified version of Groups.io.