Another problem with shortening from the top is that they don't always do a felled seam by stitching. Some I have been given are
glued and then top stitched. I would not have attempted it if the person had not also wanted the shoulder seam shortening, which means recutting the armscye - and there is not enough height where you want it redrawn. Yes, he was a very unusual shape so could not buy a smaller shirt. Absolute nightmare, don't go there.. It would have been easier to make a shirt to measure, but I was careful not to say that in case I was asked to do it.
Normally, I'd go for the cuff end every time. Something very satisfying about setting in that little placket -how sad it that?