Not sure what the "official" answer is, but I had my prior 5er for 13 years. It had a couch and dinette on the living room slide. We used it many times closed and DS liked to 'ride' on the couch when I put it in and out. Never had to have it realigned in 13 years.
2016 Coachmen Chaparral 390QSMB
2011 F350- CC, DRW, LB, PSD
2016 nights camped: 40