When I purchase my 2015 CL21RBS I contacted the factory and got structural drawings for my trailer, but there were no electrical drawings available. This was before the first move and Scott was still manager.
I ordered two additional doors to add to the camper. Challenger was great to deal with and there was no minimum order. The shipping seemed a little high, but after seeing how they were packaged, I understand.
We also have a 2015 CL21RBS trailer. I changed the two vortex fans with Maxxair fans. They have 10 speed fans that allow the units to operate very quietly. I am very pleased with the quality of the fans. They are not cheap. The units we installed have a remote and can be operated when it is raining.
2015 CL21RBS with aluminum roof. Replace two of the Chinese fans with Maxair fans. You do have to remove all the fan pieces the trim pieces are different. I used Duraflex tape for sealing the roof sections. Wasn't that hard.