The tight spot risk is NOT backing up . . . it is going forward !
I have a slider that I always use for a bunch of reasons (see previous posts) when backing into sites. What caught me by surprise was getting boxed into a sharp left hand (U) turn.
All of a sudden, the trailer was tight to the truck, in the blind spot behind my left ear.
Didn't touch ! But came within an inch !!

Something to think about for those with short box trucks . . .
Rob