Maybe this Idea might actually helps a bit the dynamic queue quality game and also it's time.

So i was watching the video posted about the dynamic's queue problems , and when you talked about the trade off on reducing the q' times over the quality of the games( Role selection above everything), yeah as Scarra said sometimes you got to play your secondary roles multiple times in a row... But why not give that chance to the player? maybe a notification that you got a match ready as SECONDARY role where you can choose to accept it or not, If you don't want it you go back to the q', and following as longer time to get you a match, but that gives you an option.