I added rear exhaust to my X2 without cutting anything. I simply used a hole saw on the inside and outside. I used a piece of aluminum pipe for my exhaust longer than I needed and cut teeth into it. I then used the exhaust pipe to cut the foam out, cut the teeth off when I was done. You can do the same thing with a scupper if you like.
Make sure you know the risks of a scupper. They let water out, which means they let air out too. When your ski is up-side down, the engine compartment retains air creating buoyancy. Scupper allow that air out, extremely fast, so you ski swamps faster and is more likely to sink completely. This is why your stock hood tubes go near the bottom of the hull, to be above the water line when the ski is up-side down. Properly installed pole breathers do the same.
Scupper's also leak where bilges do not, which matters if you break down. Fewer leaks means longer floating without power.
Lots of people run scuppers. They are animals/machines that go hard and don't stop. You might install one and love it. The rest of us love that bilges give us an excuse to get a breath in during the ride.
I'm also not a believer in reinforcement unless you are inverting. If you are not rolling or flipping, then you likely don't need very much reinforcement. A lot of riding can be done without it. People do break hulls and that old square might have glue deterioration, but don't get caught up in what everyone does because of what they might do. Be realistic about your riding. If you want to start learning that stuff, then go for it, but I was talked into a lot of mods on my X2 I never really needed. Plenty of superjets are abused in the surf without the unnecessary weight of reinforcement. Give the hull and pole base some consideration, but don't do it simply because "they" say you "have to".
So, just a little nay-saying to offer some counter points. If the mods are right for you, go nuts.
