countrycampers I might add... Our pop-up had a hinged entry door (for full height) so there was NO door frame header to hold the back box of the camper together at that upper open place. Over time, we began to see a "spreading" of the box due to that and it affected how well the back door would seal. I felt there would be great difficulty in strengthening and squaring up that problem area so we sold the camper before it became too bad (yes I shared that with the new owner).
Many pop-ups, and I don't know about the Alaskans, maybe different by model or year, have a short entry door that eliminates the concern. Just something to consider if you choose an Alaskan or other pop-up.