Exhibit A:
I am attempting to build a locker in the square to my southwest. I have sheet metals in the locker which is three squares up and one to the west. I cannot build a locker, despite having all the materials on-hand and well within the craft zone.
Exhibit B:
I am now able to build a locker, despite being one square farther from where I was. I am forced to conclude that this owes entirely to the fact that lockers are LoS blockers. I think I’m going to wind up making everything Dressers at this rate.