Hello Timothy Boyer,
Thank you for your essay and for your work over many years on classical zero-point radiation. Your interpretation of Planck's constant as a "scale factor for classical zero-point radiation" provides new insights into this mystery. But Planck's constant h can also be thought as the 'minimal accumulation of energy' in an interaction before absorption / emission.
Using this interpretation I was able to mathematically derive Planck's Formula for blackbody radiation. Using continuous processes and not needing 'energy quanta' or discrete statistics. You can find a simple and elegant proof of this (one of several!) in End Note I) of my essay, "The Metaphysics of Physics". I would be very interested in your thoughts and comments on this result. Which shows Planck's Formula is a mathematical tautology. And not a physical law needing the existence of 'energy quanta'.
Best wishes in this contest,
Constantinos
P.S. Eric Reiter's essay, "A Challenge to Quantized Absorption by Experiment and Theory", reporting on his experimental findings is in complete agreement with this interpretation of h as 'accumulation of energy'. Or Loading Theory as he calls it.