Beyond what I mentioned in the OP, I did a background extraction, denoise, and stretch in Siril, and an extra denoise and levels adjustment in darktable.
nice photo 👏🏻 I have just downloaded Siril, and I want to do something similar to this, but I have two Siril related questions because I think they are a lot of photos to stack and I am not sure my Macbook can do the job:
How long did it take you to process it?
Did you use a "normal" laptop or do you have a powerful graphic card?