The tricky part of this rule when cutting wood/glass composites, is the glass layer is sufficiently harder than the wood core that it is essentially being cut as a separate material.

This is why I treat the glass layers the way I would cutting thin metal and use a 32 tooth metal cutting blade.

And it is only a few 1/1000ths of an inch thick so, it is nearly impossible to apply the 3-tooth rule to the glass layer.

That's true if you were only cutting the glass layers. Even though you're cutting a thicker laminate with a soft core the higher tooth metal blade is not allowing the thin glass to bottom out between teeth as it would if cut separately.

A blade designed for "wood" is not going to cut it!

Metal cutting blades also cut a finer line which I like for cutting out hatches.

Part of the key to getting around this is to use sharp blades, with lots of teeth. The sharp blades cut easily and more teeth does reduce the individual impact of each tooth. I use the same blades as Etienne, partly because they have ground teeth, where some cheap blades have stamped teeth.

Yes! You get what you pay for.

Scoring on the cut line with a sharp new utility blade will break the fiberglass cloth threads reducing delamination along the edge further.

The longer I work, the more I understand, the difference is in the details. A good jig saw set to a straight up and down cut, the right sharp blade for the job, scoring on an edge of the drawn line, and cutting with one side of the blade carefully aligned with the scored line, make a smooth cut every time.