We built waterproof boards. Mine came in 4 pounds lighter than my eps board of similar size and volume. The swing weight is night and day difference, felt way more maneuverable, turns felt much quicker especially rail to rail. With waterproof foam dings aren’t a problem, as in they don’t suck up water and get heavy and cause the boxes to delaminate and fail, this has been the issue with many of my eps foil boards. Ding free means less material and resin to seal the board. Water ingress isn’t an issue, pin holes don’t matter. Jeff Clark made a prototype 2 years ago, and even with many dings it has not gained weight. I tested it for several months and was very impressed with the potential.