Possible frame problem

[Roadhazard]

Really don't know where to start with this but here goes.
I have a 2014 Outlander 316RL bought in 2015 and while waxing it this fall I noticed a crack in the outside wall at the upper corner of the passenger side slide. This crack went from the corner of the slide opening all the way up the seam where the roof meets the sidewall at a 45 degree angle and is about 10 inches long.. I checked inside the camper and it to was cracked.
About a month after we purchased the trailer it was noted that the main frame was one of the faulty frames supplied by Lippert. A Lippert tech came out and removed the axles and welded an 8 foot, 2 X 2 inch square tube to the frame to strengthen the axle area. Evidently the frame would bend down due to the length of the trailer.
So now after having the trailer for 4 years this problem rears it's ugly head. I contacted Keystone and explained the situation....sent numerous photos of the crack. To make a long story short they have refused to even look at the thing due to it be so far out of warranty. Really? 3 thee years.
My question is has anyone else had similar situation? I'm not sure what to do next. Is it something I shouldn't worry about? Or just drive it till it breaks in half? Or even claim it on my insurance?

Any suggestions would be appreciated.