What about a custom games browser. You can open your custom lobby to the public, people can view or join random lobby’s based off game type, map type, and/or the social filter already in the game. There is a large community for custom games, but it seems you have to be a part of a group or know some people who play (none of my friends even have an Xbox). I just wouldn’t know where to start anymore. Back in Halo 3 days, seems like no matter what you could find someone in a random game that had some buddies that liked customs. Then you could form groups of friends to play all kinds of crazy customs with… Just doesn’t seem to happen anymore. So I propose a custom game lobby join/search system.
TLDR: Lobby/Game Browser for Custom Games.