It is also there to stop fuel siphoning out when at extreme angles. If the fuel can enter the pipe it can siphon . The high loop is to ensure the fuel level never rises above the highest point of the vent.
I used to have a problem with a fuel tank which resided in the RH inside of the boot of my 77 RRC . I ended having to place the vent at the very top of the black C pillar to prevent fuel running out when at extreme angles.
So make sure you replicate the loop.
Regards Philip A

