Hello I’m replacing my prefab plastic shower with a custom tile enclosure. I’m planning to make a 3 ½” shelf along the wall of the shower faucet. I would like to put the iBox mixing valve/handle a few inches below the shelf and the shower head a few feet above the shelf. This would require a bend in the line between the mixing valve and the shower head. All the videos I’ve watched and everything I’veread has said to make sure the line is vertically plumbed. Does anyone see a problem with installing the shower head supply line in this manner? Would it make any difference if I used PEX or copper?