I guess it is because the SUP market has slowed down considerably, there are now very few buyers of new SUPs, especially ones that do not seem to bring anything obviously new.
Here in France for instance, in the same shop , the Quattro Kai is 58% more expensive that the Quattro carves currently on sale.
I only found SurfKiteSup feedback at the end of
www.seabreeze.com.au/forums/Stand-Up-Paddle/Review/New-Quatro-Midlength-Twinfin-Kay-Lenny-Edition?page=1