Idea for possible LP curve

So i had this thought that popped into my head after being stuck in off roles for 7 of my last 8 games. I thought, it would be nice if I could list a main role, and 2 secondary roles so that I would lose/gain less in an off role and gain/lose more in a main role.

Lord knows i like to fill and offer "specific" lane to that guy/girl who begs for it, but i dont like being punished for his/her lack of skill becuase i was being a team player and gave up a main role to fill. Thoughts?

-Edit- Another idea, also make it so you can see the main/secondary roles of your team mates.