I finally got around to finishing my RGB stars to Narrowband image transfer pixelmath script. I have been workong on this for over a year now so now its time to get it out there. You can download it from the below link. Enjoy and please feel free to comment.
RGB Stars to Narrowband Image Transfer in Pixinsight Download:
https://drive.google.com/drive/folders/15zRH1p2Xn2ReUJj7bNVCFGQ1yA_JuNnJ?usp=sharing
Star Reduction in Pixinsight Download:
https://drive.google.com/drive/folders/1qjJFliMgSoPUe3zaPG5NeXyIDNR_RQ4Z?usp=sharing
Star Reduction videos:
https://www.youtube.com/watch?v=rM3-yAcAbZc&t=326s
https://www.youtube.com/watch?v=4rhvHEBmjcM&t=12s
Notes: If your "Blend" data is halo dominate which is mainly caused by method-4, you can change the blend modes to your liking
P.S. One more thing I want to address that I forgot to cover in my video. You dont have to only use a narrowband SHO image for the transfer, meaning, if you have a OSC image, you can color correct that image for star color, then create two copies, one for a basic starless of the main image, the second can be color corrected starless to show of your dual narrowband data. Then use my math to bring back the stars but more naturaly. Hope that makes sense :-)
**Update** The download link will be updated with revisions, therefore the math in the video will chanage accordingly, but the concept of how to run the pixelmath script remains