Most definitely you should other achievements as well. For example inside treasure hunter, there a lot of events and bosses to kill for the collection. Of course it requires lot of WP jumping and checking if events can be started or is starting etc. That said, I would love to join you on your event Kitty, but event time won't work for me or I would have to arrive always at least hour later. When your event starts, my workday ends and I have been sitting on my ass front of the computer by that time at least 6-7 hours minus short breaks (coffee coffee coffee). And time to time I will be at office and not a home doing my work on Wednesdays. Anyway I'm just one guy.
Otherwise love the work Kitty. If I would look my numbers how many have attended my events, participation goes up and down for sure. I would say, advertise your event more and ask also others is the time for event good or not.