Adding Ha to broadband reflection nebula

Jeffrey Nibler

Using Adam's techniques, I do well enough adding Ha to broadband galaxies. But my current use-case is a bit different in that my target is a reflection nebula that has some Ha regions around it. I want to bolster the signal of the Ha regions, without negatively impacting the reflection nebula. 

I have tried two approaches, the first being to use PixInsights method of simply changing the R channel of the RGB image to be ~50% R and ~50% Ha then running SPCC to balance the color. The second method I've tried is using the ImageBlend script with Soft Light blend mode. I've also seen Adam's videos on ImageBlend with masks - and I thought perhaps I could use a mask to mask off the reflection nebula so its colors wouldn't be impacted negatively by the addition of the Ha data, but I haven't come up with a good way of masking this (the technique shown for the Rosette nebula relied on colors that were easy to create masks for IIRC and aside from using clone stamp to create a manually drawn mask for the reflection nebula, I'm not really sure what to do).

I have attached the output from some very rough-draft processing attempts with not a lot of fine tuning on curves and stretching, no BXT, etc. But I did take some time with ImageBlend trying to get the sliders perfect. I wasn't quite able to achieve a result I was happy with using Image Blend. The Ha region isn't colorful enough and the reflection nebula looks over-stretched. I'm sure this is a function of the slider settings in ImageBlend but it seems like a certain amount of stretching is required in ImageBlend to get the signal you want from the base and blend images, and I'm just not finding the balance between the stretch and the blend.