I have two sections of nomex honeycomb. It's a 2 pound density "paper" covered in phenolic resin. It's amazing stiff for being mostly air.
I intend to bag a layer of 4 oz Zylon on the bottom and intentionally leave the resulting dimples, but I want the deck to be smooth.
The only way that I can think to do that is to prefab the first layer of deck lamination and the bag an external layer over that.
This is 6 oz FG in epoxy. Don't let anyone tell you that epoxy is super stiff
It's a medium soft plastic, but is stiffer and stronger than polyester.