Suggestions:
Im just going to list some roles that imbalances the whole game any type of sleuth, Protector,1 player's vote count as two,person that can speak/revive dead and killer crewmate. Maybe add a jester? It ruins the "Oh 3+ of us are confirmed? Lets just vote everyone else thats not us" and "idk what im doing so letz just vote dis guy".
i don't know any other roles that can fix an imbalance
Jester can either do this one or that one
Appear randomly so its unpredictable or just a on/off button for jester
Instantly win by itself when voted off or Instantly win if voted off but can kill a person of their choosing(or just make it so that he can roam freely as a ghost and have a 1-time kill button)
and/or a time limit to prevent lessen grouping up preferably 20-45 mins.
(Side note: imo)