Nope, I think I've got it pinned down pretty well.
Well, you don't.

The OP knows that's how it all works. You aren't telling him anything he doesn't already know.

He's saying the way it works is flawed and is showing why.

Look at the cast bar to tell you when you're out of time. Not when the aoe disappears.
Unfortunately, you kinda need indicators to let you know where to run or where NOT to run. And if those are appearing late for whatever reason...