This free online tool looks very good, http://dso-browser.com/.
I think it needs a quick to import a observing plan.
We need a way limit exposures below a certain altitude. A free planner is real nice.
I was reminded of this last night. My guide star was lost when the object went behind a mountain peak. It was perfectly clear but SGP shut down the session. I had more objects to imaging at higher altitudes. I use the safety monitor which was safe to image.
Is there a setting to prevent this?