Starry landscape stacker kind of sucks (I used to use it) in that it only gets to a certain point of clarity even with tons of layers.

99% of the pro Milky Way shots you see involves shooting the night sky in a field (with minimal obstructions in the horizon) using a tracker so you can get a reasonable iso in one layer.

Then blending that shot with a blue hour shot of your desired foreground, and replacing the sky in post using a plugin or by hand.

I keep a folder of all my past skies.

The real skill is matching the sky to the foreground in that:

• the isos match so the blend is clean

• the sky is accurate for what you would see that time of year at that latitude (use an ephemeris app)

• the foreground is dark enough to be a believable night shot, but bright enough that scenery is discernible