I think you'll find that the butty-boxes are essential! As everyone knows, the huge amount of 'hot air' produced in the freight-bay after the consumption of the said boxes, adds significantly to the lift produced by the ac wings.
This is the real reason why the old 'MOTS Part 2' (or its modern Tac SOP (?) equivalent) allows us to reduce the drop speed below 1.25 Vs!