[KenWittlief]

I think maybe you want it the other way, if I understand the concern.

if the vent regulator is set at 60 psi, and the main regulator is set at 60psi, then when you goto switch the direction of the cyliner, the vent regulator will spill all its air, because its being pushed backwards with 60psi from the main supply

if this is the perceived problem then you would want the vent set at 60, and the main regulator at a little less - so that it cant force the vent side to release its air. To make this system work you have to be in control of when the vent side lets air out, through the second single valve - you dont want the extra regulator venting air unless the system has been externally stressed.

I cant wait to try this!