I use Lightroom mobile for all of my ProRAW photos and I have created presets for the Milky Way and astrophotography I do with my iPhone. Here is a screenshot of a raw and edited image in Lightroom. I would use your desktop with Lightroom or Lightroom mobile. I can help you with some preset settings if interested. Unfortunately Lightroom will not allow me to “share” a preset, all I can do is pass the settings and you can save it yourself after you apply them to the image.HEIC. I did take a few with pro raw, but I do most my edits in snapseed for its ability to do quick edits, but it does not like Apple pro raw. Imports incorrectly. But the Apple pro raw images were sharper, but much grainier. Maybe I’ll try and see what I can do with the pro raw using another app.
so far I haven’t found an app to edit ProRAW with that works as good as Lightroom mobile.
The shots were grainy because there wasn’t any aggressive noise reduction applied. That’s raw for you.. you’ll have to apply the NR to your liking. A 30” shot at iso 5000 will be noisy.