I was only going off the manual and must say I have had no issues guiding with my 60mm guide scope. This is the direct quote from the manual but everyone’s set up is different. “The preferred guiding mode is 2x2 binned, as this gives both fast downloads and high sensitivity without any ‘interlacing’ issues. The ‘Fast’ 2x1 mode is also useful if you are working with a short focal length guide ‘scope, as it offers somewhat finer RA guiding resolution in the X axis if this is oriented East-West. If operating with a very short focus ‘scope, high resolution mode may be best”.
whether it purely relates to their own guiding programme I am not sure.