Lots of places where the Viper could go on a diet.

Rudder boxes are extremely heavy and very old school design. What is wrong with carbon or a diet here?

Centreboard construction could be updated. Seems to be a case of just add more stuff rather than reviewing construction process.

Look at the moth foils for instance. The Mach2 can support a man pulling them, http://www.mach2boats.com/images/stories/foil%20bedn%202.jpg And that includes the loads also being on the join between the 2 parts of the foil. These foils are expensive, but that is due the flap and other parts of the foil which include moving metal rods, bell cranks etc inside, so the build is more manual.

Building a proper Capricorn blade which is the same length can be done and weight loss achieved. Same for rudders.

Beams are straight from the F18. But are there alternatives? OK to have heavy beams in the F18 as you are building the platform to be stiff and as close to the 130kg platform limit as possible before you add the rig. Heavy beams are an easy development here in the F18, but is that directly translatable to a smaller and lighter F16?

These are just starters in my opinion. For a great design, there are just a few too many compromises to make it a brilliant.