Messier 42 (Orion Nebula), using BQ Octantis' methods

In this topic, BQ Octantis described a method of image processing prior to stretching that seems to produce a somewhat better quality image. Here I attempted to reproduce his recommendations.

Acquisition:

Bortle 7 skies
Nikon D5600 camera (unmodified)
ISO 200
Astro-Tech AT102ED refractor, 714mm focal length, f/7
HoTech 2" SCA field flattener (1X)
iOptron CEM26 mount
30s x 361 frames (3h)

Processing:

Siril 1.2.1:

Crop to 5800 x 3800px
BQ Octantis' procedure of white balance, background subtraction, histogram conditioning, and black clipping
Generalized hyperbolic transformation stretch (3X)
Saturation

RawTherapee 5.9:

Defringe tool (to reduce blue in star fringes)
Luminance noise reduction

GIMP 2.10:

Luminance curve
Saturation