The SVT being 10.2 Compression then adding boost makes it exactly what the J&S was made for , even if the tuner does not push the limits of the tune and you go with that tune for 93 and pay for 93 and get 87 your engine with out the J&S is dead ,The J&S will let you know by the lights that there is some timing being pulled and if the lights go far enough you will know there are issues and to lift
Tunes dont change but the information that the ECU gets as things ware and get dirty does , some of these things can change AF and or timing and the J&S can again let you know that something isnt right
A 10.2 engine is far more prone to spk knock then a 9.6 and when you have to turn off the knock sensor you take away any safety the engine had and thats where the J&S comes in