Hey Tony,
Original coring was balsa endgrain between a top and bottom of glass. It's possible that this composite is stiffer than solid laminations of glass and plastic, but in no way stronger. If you have 1/2 to 5/8s inch solid laminate, you can land jet fighters on it. I wouldn't quibble except for the weight factor. It sure is the correct deck for anchor work.
Seems to me that pvc foam cores would transmit light thru if the gelcoats and/or paint was removed. Haven't tested this out. But sunny amber colors do show thru where repairs and thruhulls have been plugged on 338, and have not been topcoated.
May I suggest the scientific approach? Clear the decks of all current projects and stomp the hell out of it. Might cheat and land with your hells when you jump. Repair holes with favorite modern overpriced materials.
Epoxy likes to stick to pvc foam. But I have not ever seen the tenacity that polyester and glass has for end grain balsa. When you isolate balsa from moisture it's a grand strong deck. The parts of the deck that survived Pearson piercings in the way of track and hardware are still going strong after all these decades.