The Cathedral set is great fun. Unfortunately, the bases of the Triforium tiles are too wide–they won’t sit on top of the tall Gothic windows. (The windows sit perfectly on top of the triforium, on the other hand.)
Printing walls (e.g., Castle set) will let the triforium sit on top, but again the extra width extends beyond the wall and looks terrible.
It would be more useful if the triforium base matched the Gothic window base, because then everything would line up. One edge of the base needs to be narrower (see photos).