Dont believe what they said on paper.
I just send my LG urbane for repair due to display issue. After I receive it back, the first thing I notice is I have a new leather band. Also, I found that my watch OS is back to 2015 version, I opened it and looked at inside, it has a new motherboard, even the casing is new. But on the paper, it said they change the lcd only which is completely wrong. My watch is a completely different watch now.
As far as I know, almost all repair center, except xbox department, would not desolder and resolder electronic component, because it cannot be done by hand, and it has to be done by machine. I know one guy who work on samsung also told me they would not do that because they dont have the machine.
It makes sense that it is not cost effective to hire an operator and buy a 200k machine just to do desolder and resolder while this cost can be used to manufacture large quantity of motherboard on daily basis.