Originally Posted by
MARV
Its been my experience that an offset tenon is more common in the trade than not. But, as you are suggesting, with a centered tenon, you would have programmed one operation for both sides. You are also doubling the error if there is one.
Most of the work that I did over time involved a mortice milled with a single cutting tool, one pass. A proper fit, tenon to mortice, then mandates a close tolerance tenon (the only part in the assembly that might have a variable). An approach that wasn't dependent on an exact milling of the thickness of part was often the more acceptable path. And with using a common reference surface, you side step that issue.