Over-processed as always, this is 40 25 second shots at ISO 800 through the Z61(360mm f/6). Processed with siril’s photometric colour calibration then the black point raised .2. Of the 40 shots, 30 had dithering applied. That’s easy to do, just a button in Backyard EOS, but i can’t see that it made a difference.
Below is a comparo where i processed 10 images with no dither(ND), 10 with dither(D10), 30 with dither(D30) and the whole lot(ALL40).