I would carefully consider where you put inspection ports forward of the main beam if your boat has a forestay bridle.

Forward of the main beam, a cats hull acts like a cantilevered beam. The deck acts like the web of the beam and is subjected to shearing forces (as opposed to tension (outboard side) or compression (inboard side)). Cutting large holes in the deck without careful positioning or reinforcing probably isn't a good idea. The shear force in the deck is the same from the bridle attachment to the main beam. Plastic ports don't have great structural properties.

If it has a forestay foil like some of the nacras, it is less of a problem in my opinion. This is because the deck is then predominantly subjected to compressive loads which the gunwales (and their extra connection laminate) should be able to withstand.

Having said this, I don't know much about a nacras structural properties.

From a purely structural point of view, a better place would be on the outboard or inboard side of the hull, much more effective area of structure remaining once the cut is made.

Looking at the nacra photos with the decks off, if glued back on well, they will be structurally effective.

Sorry for the rant, I've recently destroyed a hull, same way as airborne, and would hate to see someone put a port in such a dubious place without knowing the risks.