Adjustable angle off attack on the boards, how cool is that?

YES - 1 more thing to have set wrong on your boat

Good to experiment with though, particularly if you are not sure if they are at the right angle of attack for the conditions. Fixed cases = 1 option.

Pops up every couple of year, never breaks through.
How is a person called who doesn't learn form mistakes in the past?

Persistent.

Depends if you ever figure it out. Thomas Edison failed at making the lightbulb, (I think), over 1000 times.

Ok but Edison was looking for the bigger picture. He wanted to make electrical light and was looking for the technical solution. The reason why adjustable boards fail, is because people just look to make things different or adjustable boards for the reason of adjustable boards. If you look how to make your boat faster you will come up with good ideas.
By the way there is still a huge potential in board design, if I look at the current "state of the art" at beach cats...

Cheers,

Klaus