We had an NT 26LRSS for 2.5 years. After the 1st year I noticed the front cap was getting wavy. Didn't think too much about it. I always made sure the caulking around the front was good so I figured it was just buckling from age and being exposed to heat and cold. My understanding is that the front Filon isn't fastened solid to the framing on the front and has a tendency to buckle easily. In the right light it looked horrible.
I did however notice two spots on the rear that were starting to bulge out some. Both about 3-4" in dia. Neither were close to a light or window. FWIW I'll never own another trailer without a solid fiberglass front cap. Way less chance of delame or separation of some kind.