I removed my guide scope and camera and went all in on unguided imaging. I don't really mind guiding, but it's nice to know it is not strictly necessary. I got some H-a with 5 minute subs which had perfectly round stars as well, but I did something wrong and they are not flat, so I did not include in the final image.
Bottom line, with this mount and a model, I can image at 860mm FL and up to about 5 minutes with round stars.
Details on ABin