I have contacted the boat builder who said that he now works for the company that manufacturers the Duflex balsa cored panels and mentioned that they have gone away from using balsa cores for the hulls of boats.
So he is not a boat-builder anymore, he is a rep for a company and has a vested interest in pushing the product that has the most fat in it for him/them.
Interesting how ATL still sell it
https://atlcomposites.com.au/category/26/Composite-Panels
for hull construction and the actual boatbuilders/designers are still ok with it and actively push it for their designs
Then I contacted a few Shipwrights who advised to keep away from balsa cored hull boats and I also spoke to a couple of boat surveyors who advised the same.
Im guessing these shipwrights and surveyors are not active in the multihull or performance vessel industry.
If they were, they would not be saying that.
They, like many who comment are still back in the stoneage , their only experience with cored hulls, especially balsa, being poorly executed, contour core, polyester resin, full of voids variants that were prone to problems.
Duflex is not that.
Sooo, I think I'll leave this particular boat. Very frustrating as I really did like this boat, apart from the balsa cored hull.
Your call of course but if you really like it Id be speaking to the owners and designers of actual duflex vessels.
I can assure you, their opinions and decades of real life usage should sway you.
Perhaps give Bob Oram , the designer of that vessel and Jeff Schionning a call and ask them what their decades of usage has revealed?
https://www.boboramdesign.com/
http://www.schionningdesigns.com.au/material-choices