Bring 24 mode back or make it even a 48 mode, not just 72.
PvP Ranks could be used as tool to create a matchmaking algorithm, Frontline could start at set intervals similar to ocean fishing, creating the best balanced matches possible within that timeframe with those players who are queueing. This would allow 8man premades. You could pop 1x72 and 1x24 if there are 100 players in queue every 30min. The queue could show how many people are in it.