No offence to your tailor, but next time, remind him who's wearing the coat and writing the checks. You can discuss how open you want the quarters, and how suppressed you want the waist, and where you want the pockets, and how high the waist is supposed to be, and how much fullness you want in the chest, but the tape tells the tale of how long the jacket is.
I actually want my tailor's advice, and I really enjoy talking with him. Now, he told me that a sport coat and a suit jacket are basically to be cut the same way. It is not that he refuses to do anything I suggest, but he sees no special reason to cut a suit jacket different form a sport coat, and I do not want to insist unless I really know why.
I understand from your answer that the length is to be the same. However, it seems that you suggest that other aspects could differ. It may be a silly question, but what does this with open quartes and closed quarters mean? And in what sense should a sport coat differ from a suit coat in this regard?
The thing is that I am satisfied with the suits he has made for me, but there is something about the only sportcoat he has made for me so far that I am not totally happy with, but I do not know why. I thought it was the length, but maybe it is something else.