How about making a main multipurpose board while keeping the other boards, such as that, when a thread would be bumped on the other boards, it would be bumped on the multipurpose board
That way we could concentrate all of the activity of 4-ch on a single board while keeping the thread count low and the threads easily accessible
A way to personalize the board would be nice too, like being able to favorite threads so that they wouldn't be bumped off your board, and filtering threads, from entire boards and individually, perhaps using tags