Thanks. I did a 29 minute test flight on Mini 3 (using extended battery) with the RC Pro controller and worked without issue. Even better news is the range of the Mini 3 using the RC Pro is almost, but not quite double what I could get in the exact same location using the RC. Don't know if it is the external antennas on the RC Pro that made the difference or not but I'm very happy with the increased range.
To end all disussions about the so weak signal range of the RC and render fiddling with external antenna connectors on the RC as amateur nonsense:
... wait ... no, this topic will never end. The next complainer is right around the edge, incoming. When some trees, humidity or signal interference mess with your range, remember, it's the RC's fault.