My camper had a dry weight of over 2700 lbs. when it left Lance. The AC added later put on 100 lbs. at the front third of the camper. Full LPG tanks would add 40 lbs. in total at the front third of the camper. I added a 100 lbs. with a second battery and its frame at the rear of the camper though having the generator option would have added as much or more. A full water tank sits in the middle of the camper and if full would add 240 lbs.
Any way you look at it the addition of accessories is going to be less than 10% of the camper's weight so it does not matter where it is placed. The manufacturers all design the camper so the COG is centered as much as possible over the rear axle of the truck. They do this by shifting the location of the appliances and holding tanks and storage areas as needed.
It is not something that anyone buying a camper needs to worry about if they put a camper built for a shortbed truck on a short bed truck and a camper built for a long bed truck on a long bed truck. The only time to be concerned is when the camper is off the truck as it is front heavy with the cabover section.