Ive had this idea of a 12v12 comp format rent free and i would try to make it seem balanced.
class restrcition 1 of each expect 2 for soldier, demo and sniper you would have
1scout, 1soldier, 1trolldier, 1pyro, 1demoman, 1demoknight, 1heavy, 1engineer, 1medic, 1sniper, 1huntsman, 1spy
and u are not allowed to switch between subclass and normal during the match

Weapon bans for each class:
Scout: Crit-a-Cola, Mad Milk
Soldier: Rocket Jumper
Trolldier: All damage dealing primaries and secondaries expect mantreads
Pyro: Scorch Shot
Demoman: Booties, Shields
Demoknight: All damage dealing primaries and all stickies
Heavy: No weapon bans
Engineer: Short Circuit
Medic: Vaccinator
Sniper: Huntsman, Machina, Jarate, Danger Shield
Huntsman: All hitscan primaries, Jarate
Spy: Diamonback
Gamemodes are only koth bo7 and maybe steel or a couple 5cp and payload maps

the reason i went with trolldier ,demoknight and huntsman is cuz those subclasses change the gameplay of all classes and subclasses the most. Scout doesnt have any subclasses that switches his playstyle enough. Trolldier changes soldiers normal gameplay alot cuz u cant deal any damage outside from stomp and mg. Pybro is just the homewrecker and no comp maps have water for pyroshark. Hybridknight could be played with normal demo so i thought only allowing shields for knight and no launchers for knight so u have to play normal demo or full demo knight. Fatscout is just stupid cuz u can use ur primary but just refuse to and u should be able to have something equiped for each slot so it would be dumb to just remove all heavy primaries. Battle engi is already played in koth if u think gunslinger changes engis gameplay enough for it. Battle medic same reason as heavy and its not good at all. Huntsman changes sniper playstyle heavilly so thats why i went with it but also a rule that normal sniper cant go huntsman. gunspy is already played and runs the same reason as fat scout and battle med. So Trolldier, Demoknight and Huntsman could be totally different classes compared to their normal counterparts so thats the reason i chose those out of all subclasses. Cuz they are played way differently and could make some people to play comp who main any of those 3 and doesnt play much of the normal class but this format could be just a fun mode too cuz it can be too chaotic when 12 people per team in a koth map.