Thank you for adding Mark/Dash Riot :)
When my friends are on, I actually consider switching our party from Summoner's Rift to ARAM because it is so much fun right now. There is little to no wrong choices, every champion can have fun at this mode if they can land snowballs. Thank you for catering to the rest of the champions, the way I look at ARAM now is that it's a win-win mode where even if you lose, you can make funny plays and do your best.
Situations where the enemy team has a superior comp, hyper pushing before you can fight back are still there. But at least you can last hit minions or poke back with Mark/Dash now; giving you some safety net against top tier champions in this mode.
I wish you'd consider making the damage 50% mark & 50% dash. The spell is one of the few ways to fight under severe circumstances, it reduces stress and one-sided gameplay.
Again, thank you very much for the joy you've brought to ARAM. :')