When I interface a shirt, I don’t cover the whole pattern piece, I cut the interfacing just a little larger than the seam allowance, this is to prevent bulk when turning collars, etc.
I do this for the cuffs where I use heavier interfacing.
This is especially helpful on collars and collar stands where it can become very bulky, once again using heavy interfacing.
I also do the same on the front placket and pocket facing even though I use featherweight interfacing. I cut the front placket interfacing quite short so it won’t add to any bulk at the top and bottom. The interfacing is used on pockets to stop sagging through use and the lighter product does this well.
Cutting the interfacing doesn’t have to be exact, which makes a pleasant change from cutting the pattern pieces…