How do I train recoil management with the SIRT Training Pistol?

You can only properly train recoil management with your pistol, your particular recoil spring, and your ammo. Managing recoil and handling the gun for recovery shots is one of the skill sets for proper pistolcraft. In short, you don't train recoil management with the SIRT Pistol, you train and integrate all of the other skill sets with recoil management using your real pistol. There are other devices that have certain blowback action with compressed air, but physics tells us that the equal and opposite force that the raw energy of an accelerated bullet produces in your hands cannot physically be emulated other than firing your particular gun.