How is the longer, curved tool shown later used? How is it struck? How is the stone held/supported? Ben said this was new method he came up with in the past year, different than what he was doing before.
photos supporting this have not been release by him; and yes, it's different. there is an anvil being used; i believe it's wooden.
based on my knowledge of flint-knapping (which is limited, mind you), i'd guess that this wooden anvil is allowing him to setup a bi-polar impact.
how else do would you get this rectangular flake with no prominent bulbs of percussion without having an opposing force from the opposite direction?
note the offset of poles (the notched impact areas (platforms?)): i'm thinking that the relative positioning of these platforms can be used to control the flake path/type; many combinations can be derived from the same setup. the other main variable would be the angle of impact.
at least that is my take on it. and that will be the basis for my upcoming experiments. i just need to create multiple anvils that would allow me to test this. i've even gone as far as imagining a hybrid anvil with a short cylindrical punch that is 'back-stop' positioned into a notched area of the wood. this would give hard-material impact energy on both poles.