I tend to stay away from free cutting with a jig saw, they seem to get away on holes never end up round. I’d use a hole saw if the hole is the correct size. If not I use the optional method.

Hole saw it will cut a perfect hole here are a couple of tips:
1. Make sure the hole saw and pilot bit are sharp and if not buy a new one.
2. Drill very slow best with an air drill you can control the speed better.
3. Keep the hole saw level 90 degrees to flat plane of the deck.
4. Let the hole saw cut don’t push the weight of the drill is enough.
5. Buy the deck lid first there is a flange and the hole may not be the exact size of your hole saw bit.
6. Wear a dust mask.

Optional Method
1. Trace out the cut from the deck lid flange.
2. Drill a series of holes with the large drill bit spaced close together inside the line.
3. Cut the material between the holes with a saw.
4. File (in a downward stroke only) to the line.

(I use a die grinder to cut away the material between the holes, but I’m use to working with one and can handle it well, not for beginners.)