Before I piece something together, just curious on your setup/kit…
The original blue arm nozzle snapped a few times already so looking at rebuilding the setup. Maybe a manifold with 2 valves. I cut alum/wood/acrylic/etc so the air assist would help, plus would like to keep them separate.
You could do the Lube Cube and have the best of both, If you turn the dial down you will get air only, turn it up to get a mix.. I know you mentioned keep them separate but as one unit, you can get the 110v solenoid and use the original coolant output and not have to modify any wiring and add valves and such.