I've just begun taking astrophotos and this is an amazing photo. The weather hasn't cooperated much lately so I'm trying to understand using Siril as well as everything to do with my new telescope and camera. Did you also have a dew heater on your camera/lens? Did you take flats and bias and darks too? Sorry if too many questions, you just seem to know what you're doing as that photo shows.
P.S. I don't see any elongated stars. Ah, wait, I looked at the full res version on telescopius and I see the elongation. It seems to radiate away from the center of the image in all directions. More so as you leave the center. Something with the lens?