I went back and found many installation pics in the early posts, it looks like there is no "right" way to mount the equipment tray, I see the supplied tray used creatively in every orientation and position, plus many homemade examples. I see that they are not structural, so I will glue in the bulkheads and use screws to attach the a tray to them.

I talked to Todd at Dreamworks today and it is much the same with the Airpower Multi Funtion Valve. Choose sequence timing and failsafe pressures that are long enough and high enough to do the job. So I will have to experiment with that. He prefers to use the pulse braking.