So how important do you think it is to fill the voids in the foam joel?
for a console, above the waterline, probably not very critical. Below water line, it can result in a world of trouble
Thinking of honeycomb which is full of voids the real goal is to separate the skins.
the honeycomb has a scrim on the surface that is melted/welded to the cells, so the effect when you glass over it, you are getting all the same surface area - thats the idea anyway
The core isn't really providing structure, right?
with composite sandwich, the core (properties) are critical to making it work. What makes the core work as a core and not just a form is its ability to stay attached to the skins. Voids on one side will make a place where skin could buckle.
For the console, I would not worry about it too much. Just make sure the scores are filled all around the areas where your going to mount that top