Featured Game Modes In Custom Games
Simple. Why not allow featured game modes in custom games? With it not being a matchmade feature it would not have as significant of a pull from the normal queues. And then we don't have listen to them bitch to bring back urf mode for 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 time even though Riot has clearly stated the reasons why they don't.
Apart from that, I think it would be beneficial to serve as a relaxed, fun focused game mode that you can play with your friends when you don't want to play a ranked game or normals(considering like 75% of all players treat normals like its ranked and the end of the world if you lose).