A Gerber sofa would work for all hallways that are X amount wide or wider, wouldn't it? Given how it slides over a corner.

Also a Gerber sofa is based on a flat 2D world. Tilting the sofa to get around a 3D corner seems a reasonable solution.

Presumably there's another Sofa design for the maximum that can get around a 3D corridor corner (and what height do you choose for the corridor given humans tend to choose corridors that are taller than they are wide?)

Of course, but it's only the biggest possible sofa for a certain size hallway

A real self respecting department would (a) order the sofa, and then (b) get Buildings&Grounds to adjust at least one of their lunch room-adjacent hallway corners to be the minimum size it fits through?