scopemeister
If its helpful. JHM left the cars ability to be more swift in S mode left unbuffered so that means that with the big added jump in Tq from the JHM tune there is no buffer. The D mode allows a different OEM TQ delivery. So you had to put the car in S mode for the past 10 years due to the OEM tune being so restrictive. I say give D a shot for a few days and see how you like it.
The difference is D and S is how the throttle acts. This is like this on All Audis RS4 S4 S5 S6 S8 RS7 etc. with the JHM tune your going to be able to make more Tq with less throttle input so it might be something to try.
Or if you are really set on not takeing it out of S mode… and I feel you there because I love JHM S mode in the S4. Just remember in S mode you dont have to give it the same amount of throttle that you gave the car before getting JHM tuned