Ranked idea: bonus LP for doing well the first time in ranked with a new champion

Premise: i've read many complaining about players trying out champions in ranked.

So, what about giving bonus LP (or IP or even RP) for doing well (maybe a score of A, B+, or better?) on your first ranked game with a champion?

Pros: -more champion variety both in normals and ranked (due to practicing them) -people will have an incentive for taking champions in ranked only after having practiced in normals -player versatility gets rewarded -the system should be able to adjust (being a ladder system)

Cons: -?