A few things I've seen players suggest balancing AR:URF after they're (most likely) salty:
* Give Bans - I'm not sure this can be implemented with the current set-up coming from ARAM but idk.
* Disable X Champ - Some champs I agree have a large advantage (i.e. Eve, Graves, Fiora). But i'm not sure about disabling all together.
* Add Earlier FF - This one I'd have to say I agree with the most. ARAM can have unfavorable teams (and is shorter) so early surrender is necessary there, and I feel it's a reasonable assumption that AR:URF is the same but two fold with champion's enhanced capabilities.
* Nerf X Champ - There's quite a few I'd agree with, but this is only a featured game mode. So it's up to Riot if they want to sink the resources into polishing a side game mode that's already unbalanced in nature.
This is from 21 games of AR:URF I played with occasionally the same players.