Help: Aft Deck Port Hole Over Solid Foam Block

Over the weekend I proceded to cut two holes in my post 1972 Sunfish to install a 6" deck port aft of the splash coaming and a 4" deck port forward of the rudder assembly. Needless to say, I thought I had done sufficient research and study to install these without issue.

Unfortunately upon cutting my 4" rudder deck port I realized that I had cut a 2" hole (with a circular hole saw) directly over the foam flotation block, exposing a solid block of foam and no free space. My main goal for installing this 4" deck port near the rudder was to aid in the drying of my Sunfish (foam is very water logged).

What is your advice on how to procede from here?
- Should I patch this hole and cut a new hole?
- Can I safety cut into this foam enough to provide for circulation without hurting the integrity of the foam?
- I can see free space just aft of my cut out, should I procede to widen the hole to reach the free space behind the foam?

I attached two pictures to help gauage the situation.

Thanks in advance for all your help.

Been there, done that, several times. Dispite the diagrams giving block placement we found the guys at the factory don't use a template to locate them. Not uncommon to end up on top of a block. We normally just do some carving so we can access the floor to sop up any water. If you can see open floor you have enough opening for air to circulate and dry the boat out.
The common spot we found (which is a little late for you) is to locate a rear port directly between the bridle mounts. We found that avoids blocks, or only hits the end of one in most cases.
As to trying to fill the hole and redrill, if it were my boat I wouldn't bother.

just take a knife and open it up a little, foam is just on the top side.