Am I right to assume that if you split the difference between the stop to stop turns of the steering box and the indexing spline is not at the 12 o'clock position that you should continue to turn it to get it there in lieu of having exactly 50% of motion on either side of the centered position?

then shoot to put front wheels straight ahead while maintaining tie rod length on both sides close to equal before going in for an alignment?

If the master spline does not align straight up when the box is centered, theres a problem with the box