You say that you have many dot/comma pennies. If it's no trouble, would you mind looking to see what percentage have a die crack present, please? And if everyone else could do the same please. Perfectly round holes near a die crack.
As a collective of the top coin experts, with a combined collection of the best coins to be seen, it should be possible to establish whether the dot is deliberate.
And not just pennies. The theory should apply to all denominations.
Apologies if I've become boring.