J_R,
I've encountered a number of aircraft, biplanes in particular, where hte horizontal stab is NOT set to zero degrees. Your advice will not work in those cases. I have a Great Lakes kit for example, where the horizontal stab incidence is NOT specified, but it clearly states in the instructions NOT to use the stab as a reference for setting the wing incidences.

I would highly recommend using that "datum" or "thrust" line for setting incidence on any plane.
Dennis-