I think im answering my own question, but will still gladly take tips.
After reading the manual, looks like i could just add a Tee to the line going from the tank to the valve and then insert a 12v pneumatic solenoid before going to the dump port. I was thinking that i would do normally open so that if a fuse blew or something my bus would be less likely to kneel while driving.
It looks like a lot of kneeling buses route the parking brake air supply to this port to make them kneel when the parking brakes are applied.
Im also thinking of adding an air gauge after the height control valve as i want to know what my weight distribution is at a given time.