Yes. TrueBrake works perfectly with Gran Turismo Sport.
Gran Turismo Sport on the PS4 does not have in-game brake pedal calibration which has caused this question to be asked frequently. Games that do have pedal calibration can make use of the last 1mm travel of TrueBrake but I would consider that a bonus for those games rather than a setback for GTS.
Most of the testing and development of TrueBrake was done on GTS over 2019. Its a tough job but someones got to do it! 😉