The one I am having done has something like a baked bean tin at the lowest point that Pokes out the floor of the car so even if down to the last tin full of petrol it has to be in the can (sump) that then feeds the single pump.

The sump is baffled to help hold the fuel in and the tank has anti flame stuff

If you have a swirl pot you will need a lift pump unless the fuel cell gravity feeds the swirl but I cannot see a reason to do that.