HS

For me, it is hard to tell because of the minimal time showing the die.
We don't always have rubber right up on strips; it depends on the effect on the sheet.
The NOS could be but again it's not long enough or close enough for me.

There are jobs, for various reasons, that may be scored before being sent to a folder.
(for instance: a booklet cover where there is a very distinct line that is going to be very apparent if it isn't folded exact.)
The most likely, the stock doesn't fold exactly because of the stiffness of the stock (or contrary grain in the sheet)
OR
The stock has a top coating that makes it susceptible to scratching and the pieces will actually be folded by hand.

It is a fact paper supply is all over the place for many reasons and not all of them are good reasons.