Hi Grant, sorry I missed your reply and the questions,
The AstroArt Documentation is within the help file of the software, some of the items I had put into the script were not documented as they were not yet released but Service Pack 4 has now come out so if yiou update to the latest version they should all be there to read.
The focuser compensation is as you surmised to compensate for changing temperature.
Part of the automated script produces a csv file and that stores focus position and ambient temperature data as two of the fields from that its easy enough to work out how many steps are required per degree C of change and then put these into the AstroArt Focuser control section to allow it to automatically adjust the focus position. i think I have set it to adjust for every change of 0.2 deg C, it does this automatically in between images.
Regards,
Wayne