For example UI mods, would it be easier to simply ban UI mods and integrate those that are allowed on a case by case basis once approved and then add the adjustment of those on the options screen rather than the lobby screen?
Are you going to contribute in order to implement those UI mods ? To make it clear, i'm not telling contributors to work on that or that, unless it's really game breaking (eg the free ressource generation we fixed few patches ago).
Most contributors just code something that interest them, and there is no way to tell them what to do. Only thing i can do is to promote stuff that would be important to fix/add.