At the risk of creating a black hole which will swallow us all up, could this Indigo plugin be used to shut down Indigo itself?
My problem is that I supply my Indigo Mac Mini via a UPS and I have the Energy Saver preferences set to shut down the Mac when the mains has failed and the UPS battery has only 2 minutes left. This results in a orderly shutdown before the power fails, which protects the Indigo database, but the Mac only auto-restarts after a dirty shutdown - so when the mains is restored the Mac stays off.
If I can shut down Indigo in an orderly manner before the UPS battery is exhausted I could then just let the Mac do a dirty shutdown when the battery is exhausted, then it would reboot when the mains was restored.
First world problems, eh?