I'd use the return line in the system if at all possible. The small lines used in the tank venting system are barely adequate as it is. Without the return line circulating and cooling the fuel you will probably have cabin fume issues.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now