Suggestion for One For All changes
One of the frustrating aspects of One For All is that premades can bully picks. I'm not a bad player (not great either...just not fantastic with champs that require spot on mechanics), but when a 3 man premade picks Lee Sin and then I have to go mid against a Lux, it honestly tilts me a bit, primarily because I was pretty much forced to play whatever they wanted.
So here's my suggestion:
Make One For All similar to ARAM. Your champ is randomly selected, and each player can earn re-rolls. In a queue, a re-roll would require 3 votes from players that have a re-roll available. If 3 players agree to re-roll, then a new random champ is selected for the 5 man group.
That way, it would be more difficult to be bullied by premades, and it would add a twist to the One for All mode, which in my experience has grown very toxic. Instead of blaming each other for "dumb picks" etc, players could only blame the random system selection.
Just a thought...