Hi,
The way I read it from the training manual is the valve bleeds boost off to delay the actuator operating.
So if you set the actuator to open at 10psi, if piped directly, then the amal bleeds off boost to prevent it opening until you reach 20.
The only reason I can think of for altering the amal is if you fit a really strong actuator to run higher boost and the amal won't flow enough to open it?
Cheers,
Gavin