Marc,
I think what they are confused about is years ago the same setup was used but there was either a sintered bronze filter or a pleated filter on the end of the brass tube, supposedly to break up any air bubbles.
As stated above, a lot of people think that the fuel in a UAT tank is usable, when in fact, the UAT fuel should never be used.
If, after a flight, you find you had to use the UAT fuel, either get a bigger main tank or shorten your flight times.
BRG,
Jon