Colin something I've found handy with PHD2 when tweaking Alt/Az or guiding focus is to share my laptop screen on to my mobile using Teamviewer. Even though the lappy is generally in the house (away from mossies/hot/cold etc
) its obviously handy to be able to easily see the screen near the mount.
Not sure if you can zoom past 1:1 though, now I think about it. Seemed like a good idea at the time....