Even the std underslung Sierra Tank with its baffles in , suffers from fuel surge under heavy cornering , not what you need as the engine momentarily runs out of fuel and goes lean . So if you go above the std position and force feed the fuel system then you will need a swirl pot big enough to remove surge in ALL conditions , this principal applies to any fuel system and any situation especially as a " Belt and Braces " factor.
Whether the tanks Foam Filled or not , makes little difference to this , my tank has a 2 1/2 litre Gated collector in the tank , but i fitted a Swirl pot just in case !
regards
Tony