[martin417]

I won't swear to this, but here is what I believe:

The valve is a pilot operated valve, with a small pilot solenoid mounted on the end. This pilot solenoid must have access to pressure at all times for the valve to function. It receives this pressure from a small port within the P port. If at any time, there is no pressure on the P port, the valve will cease to function. So, your proposal might work since it looks like you will always have pressure on the P port, but I don't know what will happen as the valve shifts and the pressure drops between positions.