Honestly I don't think they're needed / benefitial, if your spring rates and damping is set up properly, you shouldn't need to add them.
I've seen a lot of guys in the track racing FB group for ST/RS say it makes the rear too tail happy, causing issues. Nick Carl has a bunch of track records in NY and said they don't see a need for it as long as your suspension is properly set up.
Swaybars usually reduce grip on the axle they're installed on, and add grip to the other end of the vehicle.