[Richard]

FWIW,

There are some pretty universal and straightforward way to work around this issue. Air compressor relief valves are common, and used on about any small to mid size consumer compressor. This gives you and idea https://www.amazon.com/Secbolt-90-120PSI...WNrPXRydWU=

That takes care of relieving the head pressure on the compressor. You will need a check valve after the pressure relief device to keep the system pressure in the system.

Instead of the problematic auto dump water separator, install a 1 to 3 gallon ping tank in the bay with a manual drain. Loop ten feet on airline from the compressor into the tank to give at maximum effect at cooling the air and condensing the water vapor. Ok, so you have to drain the tank once a month. I have a quarter turn valve on mine with the exhaust piped to extend slightly below the frame.

I have a very similar setup which has been problem free for five years.

You will have to find a way to use the 12VDC signal to turn the system on from the Valid computer.