I've discovered an explanation for what I am seeing. It's what you called "wacky" in the Stretch Academy video: Starless Images and Stretching Part 2 @ at ~4:50.
I ended up leveraging the processes from your "DBE_Small_Scale" video where you had to deal with the bright "X" in the image. Lots of samples with adjustments for tolerance, shadows relaxation and smoothing factor. Took some trial and error, but i…