SF3300 concave hull question

I don't know how to put this, but is there any proof that concave shape of the hull at transom of the boat is working as advertised?
I got this question after looking at more recent class 40 hull lines; it seems that no-one is using concave in class 40 or imoca, or am i wrong?

 

Can you post this advertisement of the 'class 40' so we can see what the claim is

 

A thread was already opened on this issue, may be you can continue with it.
The new SUN FAST 3300 with a double concave line https://www.boatdesign.net/threads/the-new-sun-fast-3300-with-a-double-concave-line.61651/

 

i dont get it

 

yes, thanks, will do

 

It always amazes me how the old becomes new again and is called innovative, or a first. This abomination now called a double concave keel line has always worked as a way to cheat racing rules based on length and sail area. It crops up in increasingly freakish boats until the rule makers make changes to rule out such horrid designs. Here is an example from over a century ago, from the drawing table of no less than Starling Burgess. If you think this boat is ugly and disfunctional you would be half right. Due to a high sail area to waterline length ration this boat screams along. It is still garbage though.