As a university, we have several membership programs both current and old. It would be very helpful to only view active memberships in the participants list, especially if someone has been on several different advisory councils over the years, and the athletics boosters, and the museum members program, etc.
(I would like to define which memberships show in the column, so we can choose to only see memberships related to the event host, for example an athletics boosters event only displays whether someone is an athletics booster or not, so we can very quickly know whether to encourage the person to join the boosters, but I imagine that is a long-shot Idea. :-) for now, only having current memberships would be huge, so we can at least know that someone may have bought a Boosters-discount event ticket but aren't currently an athletics booster)