Having used dozens of lenses over the years, I can say that those images represent very good performance from a lens wide open at f1.2.
Your long focal length refractor is probably f5/f6 at best right? That bears no comparison to a (relatively) wide lens at f1.2!! In the real (affordable) world, you’re never going to get perfect stars without halos etc at f1.2.
There’s a reason why equatorial mounts are pretty much a requirement for astrophotography, although you could try stacking a series of 15 second exposures on a tripod at say f2.8-f3.5 and see how you go. Even if the individual frames are underexposed, you should be able to pull something better out of a stack of images.
Phil
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