I'll play devil's advocate for a min. I'm not sure if typical two stroke is even capable of pushing air through a full tank of gas. If this were the case, the air pressure from the muffler pushes only on the open surface area of the fuel tube, 1/8" If the same amount of pressure is applied to say 2 square in of surface area, the effective pressure on the fuel is several times greater. Hydrolic pressure is calculated by surface area x force.

Pressure = Force (Lbs)/Unit Area (sq. In) edited to insert formula.

I think, unless proven otherwise, that the Uni-flow type tank adds no measureable pressure to the fuel, thus fuel pressure is the same at the end of the flight as it was in the beginning.

Please don't take this as a personal assault smokingcrater. I have never tried a Uniflow tank, it may work fantastic. I am only trying to understand the physics behind it.