It's a tricky one, Lewis. You've done well!
I did some test shots of that PN a few weeks ago. The moon was up so I needed a bright target. I started processing and the image was looking quite good with a reasonable amount of internal detail. I got to the end of my usual workflow and did a conversion to sRGB and the PN just turned to blurry mush. All the detail was in colours that were out of gamut for sRGB
Must get back to it and try again. Maybe I'll start in sRGB next time.
Cheers,
Rick.