Nice bunch of images Steve, bit of everything including the Classic star-Trails which do appear cleaner because of the stacking, <-- hint
Yeah the 14mm is crazy wide hey, and be even wider and more distortion on a full frame chip..
I do see a bit of Green Yellow tinge in your single exposures which could be due to White-Balance setting,, might be worth experimenting with, maybe try (White Fluorescent) 4,000K <-- Kelvin should produces a more light blue tinge which may seem more natural..
Actually I just checked out (Affinity Photo) and it appears you have a White balance option in there,, could be worth experimenting with this too,,,
Nice show