Dynamic Primary and Secondary Role Suggestion
So I wanted to address the fact that primary roles do not seem to be the role we get a lot of the time. I'm sure the logic behind the role selection is quite complicated but a lot of the time it feels like when you choose a primary and secondary role that you get the position that is least popular of the two most of the time.
My suggestion would be this:
Getting your secondary role choice for a game increases the chance that you get your primary role choice the next game. This effect would stack. When you do get your primary role choice, the chance resets to normal. (This effect would be regardless of the positions you pick as primary and secondary)
It wouldn't be a quick fix because keeping track of data like that and adjusting the algorithms would be complicated, but in theory I feel like it would improve the dynamic queue experience.