I am surprised it is so hard to find a diagram or description of the proper way to rough in a bathtub spout. In case it makes any difference, the specific spout will be a Toto TS210EV with diverter.
At the bottom of the valve there is a 1/2 inch NPT male nipple (is that the right name?) so I expect to put in a descent pipe, 90° elbow and a nipple through the backerboard and tile.
But how far past the tile surface should the pipe go?
How small should the hole through the tile and backboard be?
How does one make sure the spout ends up vertical when fully screwed on?