Anyone out there tried SkyTrack Satellite Tracking Software? I downloaded the trial this morning and it looked pretty good so I've decided to purchase the license (US$9).
It looks like it has quite good pass and ISS transit prediction capabilities so might be useful even if the mount can't slew fast enough and it might add another dimension to imaging if you've already been through the NGC list.
https://www.heavenscape.com/index.html