You're not talking about the bleeding position, but the position of the spine is 1 cm.

Let's see what paper you print on first. If it is 250g coated paper, the spine of 30 pages is about 1cm, and the middle 15P gradually decreases to about 0.08MM per page, so you can notice that it can move inward by 0.08MM relative to each page, but in fact, these changes are very small, and the process is the last cut, so there is no deviation.