I dropped it off. He's doing it on his own.I'm interested in your progress. I've thought about doing something similar.
I would be very concerned about neck dive. Maybe you can check the balance after each rout to evaluate how much weight reduction vs neck dive you get.
Ya know, neck dive was never a concern because I can't imagine there is going to be enough weight removed from the body to cause that. My chambered Les Paul Deluxe is 7.3 pounds and it's fine. This guitar was 9.9 lbs so I'm hoping the end result will be about the same.
Having said that, I really don't know. We shall see.