I've been building a variety boards for 16 years using a variety of cores and reinforcements. skateboard, landboards, twins tips, mutant TT's and now hydrofoil,,,
my last kitboard build was carbon,3mm bamboo and 4mm foam core construction. it has a 7mm core at the thickest and 3mm at the tips.
I'm an aggressive rider weighing between 77 and 84 kg depending on how many pies i've eaten. I fly in winds up to and beyond 40 knots I can and do jump 10m + and ride crazy seas up to 6m swell.
My opinion after 16 years of successfully building a wide range of boards is that a thicker core (say 12mm) and less reinforecement say 200grm each side is not strong enough for aggressive riding of an 80kg bloke.
My call is to go thinner on the core, increase the reinforcement and you will have a stronger board that can handle silly conditions and rediculous hard landings.
I would destroy a 12mm cored board with only 200grm used for reinforcement within 6 months.