Manufacturers warranty their original equipment from defects due to manufacture. IF you add after market parts to your vehicle and original equipment fails then you are at the whim of the manufacturer. Remember. Dealers only get paid by the factory. IF the factory rejects the warranty the dealer doesn't get paid.
If you want to modify the mechanics of your vehicle then go right ahead but do not expect the FACTORY to warranty the mechanics if they fail once modifications are installed.
It's a choice. Get it dealer serviced and leave it unmodified. Kia has no choice but to fix it for the life of the warranty.
Do anything else and you are increasing the risk of the manufacturer WITHOUT THEIR INPUT. Whether or not the modifications caused the failure is irrelevant. It's a choice. Accept the warranty or not.