I can't speak for the EVO. My X Star could be located using the controller data. I think it would have gotten me close enough to visually find it.
Other than a catastrophic failure of some kind the Drone will generally take care of itself. The available data will keep the pilot informed of all critical things such as distance, battery reserve, etc. The Drone will even try to take over and RTH if it calculates there's a problem.
I had some battery problems with the X Star where it would go from 40%/15 minutes of flight time to "critical land" instantly. Fortunately that never happened to me when I was a long distance from the Drone. I number my batteries which becomes valuable as they get older and individually develop a pattern of discharge. I only have one battery left for my X Star that I can depend on. Which resulted in my purchase of the EVO II.