Hi Marcus and Mike. Thanks for your feedback; it's much appreciated.
Marcus - once I read your comment about the image being slightly milky and noisey it was then immediately obvious in the image! I've tweaked the image accordingly.
Mike - you've highlighted something that I'm aware of but have struggled to understand how to improve using PI's beginner-friendly, simpler tools. In essence I use a fairly generic workflow: basic LRGB combo, background extraction, simple colour correction, GHS, RC Astro's tools and basic histogram and curves tools (with some final minor tweaks in PS). I don't do any sharpening in PI beyond using BlurX. Perhaps it would help to use the unsharp mask tool too? I could be wrong but I suspect the real magic to preserve/enhance detail at a micro level lies in PI's advanced tools like multi scale processing and deconvolution. I've yet to learn these tools but reckon now is as good a time as any
And the stars hmmmm that was me trying to be clever by thinning out the dense star field, but I went too far. I'll fix that!