Damn you PI freaks!
I look so incompetent with CCDStack, Photoshop.
Layers and Masks, and plenty of them.
Colour combine in CCDStack. Used two RGB versions. Same colour balance for both but one with a high saturation. Applied while data is linear.
DDP stretched the Lum and colour masters. All exported as tiffs into photoshop. Conventional LRGB combine. While tempted to go into PI for some DBE, I opted to use Russ' gradientXterminator plugin. Applied blue photo filter as a mask to highlight the starburst regions. highpass mask on luminance to tighten. Inverse mask for noise control, I should have gone harder on reflection as the background is still a mess but this was a quick and dirty process. Tempted to liquify some of the bloated stars to tighten but decided to save them from implosion.
I actually have an M83 data set from 16" ASA that I'm yet to process. Will look into it shortly.