Anyone know how to install a PTO controlled air bag dump valve?

I've got a 2020 Freightliner Cascadia that already has a PTO and air dump bag switches on the dashboard. Trying to make it where when the PTO is turned on, it automatically dumps the air bags for a dump truck application. I thought this would be easy as the air ride control valve already has a dump valve built in with a pilot line. What I did was tee off of the air line going into the pto and tied it into the pilot line going into the dump valve. My first problem with that is the air back charged to the air dump switch in the dashboard when the PTO switch was charged. My solution to this was to put an inline check valve between the dash mounted dump switch and the tee I spliced the pto line into at the pilot line going into the ride control dump valve. My second problem after doing that is the air bag dump valve would not work properly as the check valve wouldn't let the air release back to the switch so the line never un charged and the bags won't air back up. Kind of pissing in the wind on this one. I want to be able to use the air dump valve independent of the PTO. ANyone know how to do this with my application? Got some pics for reference. Valves for PTO and air dump in the dashboard are air and not electronic.

 

I called two, they're lost. Parts guys are just parts guys these days for the most part unfortunately.

 

Tries that. It backfeeds the dump valve in the dashboard. Hoping to keep them both working as I may want to dump the bags without engaging the pto. The pto will probably never need to be engaged without dumping the bags.

 

Hoping to keep using air for everything.

 

So you're saying there's no way to keep the factory PTO and air bag dump valve and do this? Trying to find a work around. Someone has had to run into this before.