We've never had an issue with the sewer outlet dragging on anything. We have, however drug the spare a couple times. Once, it actually pulled it off (didn't damage the mount though). I'm going to be relocating it soon, though I'm not really sure where yet.
Tina + Dutch and Bell, Bobo, Harley, Buddy (the dogs)
2011 F350 Lariat 4x4 DRW SuperCrew 6.7L (B&W setup w/Air Lift 5000 Ultimate)
2014 Columbus 365RL (Airflex and Voyager package)
Nights Camped 2014 - 154
, 2015 - 32, 2016 - 4