I have a vacuum modulated transmission now (after the Pro Built Automatics Pro-Street LT1 rebuild kit) and have a question about decel fuel cutoff.

The way I understand it, the vacuum modulator increases fluid pressure as vacuum drops, so it increases pressure the more gas you give the car.

If that's true, then at times when vacuum is highest, wouldn't fluid pressure be at it's lowest? And since vacuum is highest when the throttle is closed and the engine is decelerating, that would mean that during deceleration (engine braking) the fluid pressure will drop, but how low will it drop.

Will it hurt the transmission?

Or am I misunderstanding how the vacuum modulation works?