Ports are a definate last resort as they are literally a pain in the backside when your trying to get around on the deck or being carefull to watch where you place your feet instead of your course. If you have to cut a access hole cut it with a jigsaw on a 45 degree angle then when you've made your repair resin in a bit of closed cell foam underneath the deck then resin your bit that you cut out back level with the deck into the hole, dont fill to the top with resin leave a bit of room for gelcoat with wax on the surface and your good to go. Try and do the repair properly as you wont be able to get a patch out of your dagger well easily later.
This is a photo I posted on Beachcats of the deck repair on my Stingray. It started with a port hole cut in for a repair then as it delaminated the previous owner kept adding support underneath but it ended up as a wobbly weak deck.