To be honnest
i am using tilotson heavy fuelclunks for years.
and i have a square tank.
these should be according to you all a disaster waiting to happen.
a few of you maybe seen me fly at pampa,s this year.
on most flights i would come in with the main tank completely empty and the UAT half empty.
and yes i also have my tanks lifted by a few degrees in the front.
conclusion they all drain the tank empty.
and on those rare occasions where it will take some "foam"fuel the uat will save it..
i must add that i NEVER used tygon , but just a piece of Festo 6mm attached to the fueltank and clunck.
this way the fuel clucnk will ALWAYS stay in the back