"Insights" like the one above, tend to occur when we test the boundaries of "accepted wisdom." Also, when we look at the complete coinage operation and consequences of the mechanical functions and equipment, we can begin to solve many of the mysteries that baffled past writers.
That is: "Learn then Look"
(A little more background... For a long time it was assumed that new dies were "polished" before being put into service. That assumption created a cascade of incorrect speculations which then metastasized into "official pronouncements from Experts." What I did was to go into the original records and asked "How were dies made and put into use? How did proof-like coins originate?" What the original letters said was that the final step in preparing a working die was to temper it, then dip the face into weak acid to remove any "fire scale" or surface oxide. After this dip they went into service.... The rest was mentioned earlier in the thread. A similar approach was taken toward luster, and sandblast/satin proofs, and so forth.)
Hope this does not sound boastful (I don't want it to be...) -- the information has been there for a long time, just nobody looked -- or maybe bothered to challenge the "Experts," or maybe I was just lucky.