Yes, you can cut into the deck, as far as you wish to without comprimising strength. A few shapers have commmented on how exciting it has been to be able to cut into the deck after all these years of one and two pass blanks.
I’ve recently checked out some some the newer foam. It looks good, a lot better than the stuff that was out in Feb. For me it is still a little heavy and a little stiff.
The newest foam is the same weight as the super lite, but much harder. Not sure which foam you checked out. Marcio from Sharp Eye told me the following: “when I finshed your foam next to a Clark your foam felt heavier, when I weighed it, it was in fact the same weight or lighter on occassion. Why is this Scott?” I told him and other shapers I have no idea. Michael Baron has had super lite finished boards that are holding up great under some pretty big guys who beat up their boards pretty bad. If it has a stencil mark and black tip it should be pretty lite when it is finished. Glass one and let me know what you think.