From what I understand it does it by pulsing a solenoid to bleed off pressure.
It doesn't monitor what the actual pressure is, so its just a set duty cycle thing.
You can add add larger resistor into the solenoid wiring so it bleeds less pressure off by not allowing the solenoid to open fully. At full throttle it's full line pressure so it just adds pressure for part throttle stuff. I did it as I run an rb2530 so make more torque with less throttle openings than the stock trans ecu would be expecting.