In architecture, a seam is not load bearing. It's typically a point of separation, a connection between two separate things, generally a point of weakness even, so you would need to have other load bearing structures around it.

"Load-bearing seam" doesn't make any sense.

This reminds me of an engineer that tried to explain to me that my prune tree in my backyard was in fact a plum tree. All prunes are plums but not all plums are prunes.