So I saw the client now shows an auto fill is activated so you can get faster games and more quality of play instead of waiting in a queue.
So what I propose is if people choose autofill there be a secondary option next to the autofill where you can click to deny a single role.
For example you know you do really well in top, mid, support or adc but you don't want to do jungle.
SO you select in the autofill that you do not want the Jungle role, that way when autofill is selecting a fast game it knows to avoid jungle role for that specfic player.
This could probably follow an approach most liked by players as they can for 1, get faster games instead of waiting ages for their specific role (first or secondary role) and 2 they can also deny themselves ability to get a role that they'd play bad in.