Im a bit confused about this inset clew idea that Gaastra ( and probably many others ) have brought out this year. i know its old tech blah blah so spare me.

But, what im curious about is on the picture of the 2011 vapor they claim that the inset clew increases control and provides higher performance,
this isnt the normal inset clew where the leech of the sail simply protrudes outwards above the boom and continues upward like normal, this one is as if they have got the normal outer clew position and simply moved it in 30cm

Now in reference to the center of pressure on the sail, if the clew is closer to the CoP then the moment arm ( in this case the boom ) is shorter and therefore you have less leverage over the sail. wouldn't this decrease control and leverage over the sail and therefore decrease control ability?

For example, an aeroplane rotates around its lateral axis by using the elevator ( in the case of a sail this is the boom and sailor pulling on it ) if the elevator is a long way from the pivot point of the lateral axis or center of gravity ( approx 1/3 the chord line from the leading edge of the wing, or in a sails case the luff ) then only a little amount of effort is needed to provide a significant amount of movement its just the simple leverage action really, and vice versa.

so what im getting at and i hope some sailors with experience using inset booms or perhaps some sail manufacturers could shed some light as to whether its just sales hype or does it actually make a difference??