Tried this out tonight and it works really well!
I'm stage 1 and with TSC off a 2nd gear pull causes the car to steer to the right quite a bit. With TSC active, the steering rack now automatically counter steers for you, and the car pulls straight with only a VERY small amount of torque steer when close to redline.
This is a very good find. Steering otherwise doesn't feel like it's any different either. I'd still be very curious to see how well it compensates for even higher powered Stage2 or K04 cars.