A mode that can gather people for an extended duration amount of time and let's other swap in and out for time intervals. It would be nice for times like this Christmas where I have nothing to do all day and others can commit to certain times but not a complete marathon. It should have a start and end time, and allow people to join with times that slightly overlap. And if enough people sign up it will assign create multiple teams with a shared reserve pool. Trying to fill multiple games close to each other will have some games where more than one person is MIA as people often bail in the hours leading up to the start time. A mode that dynamically assigned players
too fill vacancies to create as many viable teams as possible with the remainder as reserve for the duration of the event would be handy. Players could also limit themselves to teams with certain players maybe.

Or something that just leaves the raid open and let's people indicate their available time would be a good start.