I have been able to un-guided at least up to 15m with the following. I have not gone beyond that...do not expect to need to.
A-P 1100 / CP4 (non-AE, no HC)
APCC Pro / SGP / APPM Pointing and Tracking models (150 points)
14.5" AGOptical Corrected Dall-Kirkham...f.l. = 2500
Canon 6D full frame (Image scale = 0.55"/pxl)
Median Eccentricity (using PixInsight) across one image was 0.4552 - guided and 0.4921 - unguided
Median FWHM = 5.1 - guided and 7.4 - unguided
It took effort to move up the learning curve on the software. Getting a good PE curve was also important.