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.
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.
Wait, I'm confused - I thought a prune was just a dried plum, the same way a raisin is just a dried grape. Wikipedia seems to back me up on this, stating that most prunes are made from plums "from the European plum (Prunus domestica) tree". Do the prunes grow pre-dried on your tree?
First of all, 'prune' is French for 'plum' ('prugna' in Italian). Plums which are suitable for drying are named 'prunes' and even 'prune plums' in English. My tree is an Italian Prune (Prunus domestica) as you half mentioned. Notice that the Latin isn't "Plumus" and is "Prunus". I grew up with Purple Leaf plum trees (Prunus cerasifera). They would rot. I haven't seen fermented Italian Prunes in my yard, even the ones that the squirrels and crows have taken bites out of. You may have figured out by now that only in modern English is the fruit name conflated with the specific dried fruit product. This conflation is the point of my original comment on a narrow interpretation of the word 'seam'.
But even then, I think "boundary" was the more common term before some LLM decided it really liked "seam" instead.