KFC-AWD

In my search for a 200TW street tire for autox on a C7 Grand Sport, I've given up trying to run SS as there are no decent size 19" tires (dont want to give up a 335 rear for a 305 square setup). I figure might as well join CAM class with 18s. So wondering if people have successively used the 18" Rival S combo (335 rear/ 275 or 315 front) for Autox without having the TC go wonky? Stock rear/front ratio is 1.03 and this Rival setup is 1.01 so not sure if it will play nice with the system. So before just throwing in the towel and going with 18" A7s and run SSP I thought I would see if anyone had some feedback.

Thanks,

Scott