Suggested

Bonus / malus of suppliers.

(sorry for my english)

I don't know if anyone has already proposed it in the past, it didn't seem to me.

Although I don't have much experience in the elite category, it immediately seemed evident to me that there is a need to review the bonus / malus of the various engine / tire / fuel brands for each category.

For example, it is obvious that a +3 tire saving bonus (Komehome) in the rookie category with a cap of 50 has a different incidence in the elite, which with a max of 200 would give a marginal benefit.
Quite different, however, if the tire bonus were proportionate to the category and therefore +12.
Each manager would return to carefully evaluate which supplier to use.

For veterans of the game, does my proposal make sense?

The marginal benefit is already the advantage. Experienced managers already swap sponsors depending on the track or car development. 
I kind like the idea but the consequence of increasing the sponsors points would certainly encourage that behavior, requiring to swap sponsors constantly.