The problem, Mr Guffey, has nothing to do with whether or not "neck tension" can be measured or if the measurement is in pounds or if it's "bullet hold" instead of "neck tension".
When somebody asks if they should use 87 or 89 octane in their car, they don't need or want a break down of RON and MON, the formula for the rating and a PhD dissertation on the development of the internal combustion engine.
How much smaller than the bullet does the neck need to be? That's all.
This is a simple question. It really doesn't matter how it's measured because no one asked, 99% of every one doesn't measure it, doesn't need to and never will. Not only will they never measure it, they couldn't care less how it's done and never will.
They're not going to blow themselves up or make bad ammo if they don't know and don't care how to measure "bullet hold" and a rambling, irrelevant, non-answer to the question they asked isn't helpful at all.
A simple, functional number like "0.002 and not more than 0.003 will work" and perhaps reference to the fact that a reloader could buy gauges and directly measure, should they be so inclined, would be entirely sufficient.