As a follow-up to this since it got views, I just thought about a possible solution that I'll try tonight.

I'm thinking that since the maps on D3 are all the same size and in the same location then the lines on them should all overlap quite neatly so if I put a viewer on each of the other screens and have all 3 viewer screens overlapping in the same-spot then I should see any star that appears one off-screens pop up on the active screen. I won't know which screen exactly to look at but I'll know I can quickly stop and look over to see the shafts. Hopefully this will work as it will save time in the long-run....might only take 10-30 seconds after a batch of mobs to turn my head and check the other screens but over a few hours a night that time will add up and given legendary drops are all about mobs/hour anything I can do to reduce downtime has to be worth it, especially if it means not running marginal software.