My solution to this whole issue with Twitch's Community System would be to introduce a Tag based system instead. This is backwards compatible with the Community System. The idea would be that your stream has additional tags that specify additional information that can be searched for. So if you stream a Wind Waker 100% speedrun, you'd have these tags:
nintendo
, zelda
, wind waker
, gamecube
, japanese
, speedrun
, 100%
Now, it is obviously annoying to choose these tags, but the Game selection automatically implicitly selects the tags for this game for you, so for Wind Waker that would be:
nintendo
, zelda
, wind waker
, gamecube