Do you have TheSky 6? If so, using ACP Planner's timing features, you can see the local horizon (plotted graphically in TheSky) and avoid targets below. The timing features allow you to roll time around and see the state of the sky at target start/end times. I could show you via remote login, but maybe you can figure it out from the
ACP videos, starting with Planner 5 Using Starry Night. This is a pre-requisite to the next one, which shows Planner being used with TheSky.
It's not the same as trying a target in the blind and being told "Nice try, but it's below the local horizon for all or part of your intended exposure time", but unless I am misunderstanding something, it's actually better because you an see what you're doing and avoiding.