I can relate.
Time limits and different variations of game modes.
5 minutes or more on a certain map,lets say Shuttle Bay.
Each 5 minutes you get put in a different game mode or a different map (Same or Different game mode).
Also enabling a voting system.
Voting system would work this way,
P.S - I know everyone wants to play their fav class but be real.
You would be able to vote on which Hero should be banned and which should be allowed.
Majority of the players who choose a certain Hero,will either be banned or kept to use.
Idk,just my suggestion