The actual cape used on bale has a v cut in the back just like the tdk cape. It was designed that way because of the v in the back of the cowl. The cape does cover part of the sides of the cowl at points but it is essentially because the cape is connected the same way as the tdk suit, just with visible cape clips.
So how do you plan on designing a custom cape? You gonna go with the old "under-the-cowl-with-a-hole-cut-for-the-neck" design?