Also keep in mind that
DAS Return Times have a start time, but they are valid until the park/attraction closes for the day. If the line looks long, you can hang out nearby, wait to enter the line until it goes down a little. The CM at the entrance can also often give you a pretty good idea of the actual wait.
And, sometimes the congestion is at the line entrance, but it clears up a bit into the line.
That happened to us last week at the Safari at AK. The Line extended past the entrance to the
Lightning Lane and past the first turn inside the line when we got in to use our DAS - I snapped a picture of my watch for timing - it was 1:44pm. But, past that point, it cleared out and we were loaded into the tram by 1:50pm. That included fastening in her wheelchair so she could ride in it.
So, 6 minutes for a line we were pretty sure would be a 30 minute wait.