It does not matter if I use it with an iron core motor (high inductance). However, with coreless motor, locked anti-phase heat the motor a lot (even with 100kHz frequency). I have used 24V coreless motor with 24V supply with 100kHz locked-antiphase, and the result is that current rise up to 2A and fall to -2A. My motor is rated at 5A, but its inductance is approximately 24uH, not in mH scale.
The main reason I want fast decay is to use current prediction formula to control current of a coreless motor by controlling PWM duty cycle. The motor has optical encoder mount at the rear, so I gets its speed. To control the current, I made it such that at the ON time of PWM, current rise up, and when PWM is OFF, the current must fall down to zero. The key is fall down rate, as current must fall down to zero before next ON cycle comes. Note that current graph in every PWM cycle will looks like distorted triangular.
Accuracy of this current control method is related to accuracy of measured speed, or back EMF. With a slow decay driver, only back EMF and resistance are used in decreasing current. without high accuracy back EMF measuring, accuracy of decay time is very low. But with fast decay, there is additional decay voltage from supply. Note that my project focus on controlling motor torque by controlling current. I have successfully use this formula with fast decay driver, at 100kHz, but that driver max current limit is only 5A, So I can only use theoretically maximum current at 2.5A.
Also, a slow decay driver can not sense current when it is braking, as the current won't go through current sense resistor, So current limit mechanism won't work.
Edit: After checking IC datasheet, It seems like your gate driver IC does not support fast decay. I would like to know if you have plan to develop fast decay driver soon.