I'm very happy to report that the problems I reported earlier with recording locking up seem to have been resolved. I started and stopped recording several times with no problems.
I ran through the gamut of shots including tracking a subject, orbiting a stationery subject, orbiting a moving subject, and for the first time was able to test rails and walls.
Everything seemed to work as expected.
The one type of shot I would still like to be able to do, if at all possible, is tracking an object even after flying over it. The camera tracks perfectly approaching the subject and to directly overhead but then completely loses it shortly after that, even at very slow speed.
After playing with rails it would be great to set keyframes for flying speed, altitude, and camera position to create shots that can be repeated at the push of a button and/or designed to perfection. I believe this can be done with DJI's own software for the Phantom 4, but haven't used it so not sure.
Finally, it wouldn't hurt to be able to set walls for altitude as well, both low and high. Low to prevent accidental grounding if doing moves at fast speed where one little bump while doing a shot scraping the ground could mean a crash and high just for safety.