BTW guys, after reflection, I remembered how often we used to go onto the roof of the Kodak Research Labs B-59 or out the side door into the managers parking lot and shoot "girly pics" of a lab tech holding a MacBeth color checker. We used to use this same method for verifying the speed of our films under real world conditions.
The charts we shot at EK were read with a densitometer and placed on the aim curve to see where they fell in density vs ISO rating to insure or double check our calculations.
No, I suspect reciprocity perhaps in these experiments. IDK. Paper is generally not intended for being used at much below 1/2" or much about about 90" or thereabouts. I would think that we are all outside of this range in one way or another. IDK.
I expose and process within about 10 minutes as well so there is no Latent Image Keeping.