Nacra UK. Take a good look to these foils featured on the Nacra 15 foiling version , as is going to be the launch and test platform for the Nacra 17 Tokyo 2020 flying version.
This Nacra 15 'F' is scheduled to be sailed in Buenos Aires Youth Olympics in 2018.
Finally the restricted box rule where the A-Class developers found a solution to foil is becoming so efficient that the guys at Morrelli & Melvin are targeting to use them for the next Olympics, which indeed is a wise move to upgrade current Nacra 17.
We can trace setup above (4 foils down and L rudders) to Martin Fischer's 'Mayfly' A-Cat built by Exploder in 2011.
Edit: -- I recieved a mail saying Martin did not invented the 'Z', I didn´t wrote that above, the idea was to point that Fisher was the first designer to my knowledge to implement and target along Jakub / Exploder a racing foiling machine. many laughed at the time, and they certainly did not succeed with the Mayfly, but they set the first basis for what we have now, racing foiling cats, even before TNZ great and first effective AC solution. --
All these considerations taking costs and discussions o a change of platform without a trial for 2020.
Lets wait also for some AC further development too regarding alternatives to TNZ J foil design from last cup.
Additional info onthe Nacra 15 platforms at nacrasailing.com/nacra-15-three-versions-one-platform