That seems to have done the trick!

I didn't think I needed to put that line at the end of the program run because I thought it was a perpetual thing: The app setting a flag saying that this particular application has a feature that needs the display all the time. I hadn't realized it would be like a trigger.

Anyway, it's working now and I think I'll be using this instead of PassMark Sleeper once I parameterize it (timer value and sleep/hibernate choice).

Thanks!