It is always recommend to include a pressure hold system for a blastroom, as it has a 2 second start up and shut down, rather than 6-7 seconds. This allows the blaster to stop blasting and move to another position with minimum down time.
Pressure release systems depressurize the blast pot every time the blaster releases the deadman handle. They can only be used with one blaster, and only beneficial if the pot isn’t lasting very long, as the pot can refill whenever the pot is depressurized.
Many blasters report only get 12 minutes out of a pot of slag.