Just as an experiment, if we used my idea of two separate but connected Normal Queues, it might look like this (games slotted with guesses, obviously not set or anything):
Normal Queue (Next Number: 35):
Standard/Open Games (* denotes Tweaked)
Stack the Deck, by yuma.
Base Dominion, First Game*, by Voltgloss
Community's choice, by Sudgy
Unknown, by raerae
Adventure Time Mafia*, by ashersky
Donald's Greater Idea Mafia*, by mail-mi
Justice League Mafia, by yuma
Unknown, by mcmcsalot
Survivor Mafia (16 players, open setup), by Galzria
Unknown, by liopoil
Unknown C9++*, by Twistedarcher/nkirbit
Invented/Closed Games
Avalon Mafia, by Tables
Monsters University Mafia, by ashersky
Arrested Development Mafia by yuma
A fresh start (9 players, closed setup), by Galzria
Unknown, by Archetype
I would propose that at any given time, the top game from each of those separate designations is open for sign-up. The one that fills, takes the next number (or takes a number at sign-up stage, whatever). As one starts, the next on from that queue opens. We continually have one of each style open, and they all count for stats. If you don't like closed version, just don't play, because an open game will always be available.
We could probably move some RMM to Invented/Closed (like LOTR1 might have) or people might tweak invented RMM games to not be so crazy that they would fit in the normal Invented queue.
I think something like this could keep both mods and players happy.