I haven't been able to figure out how these work. GPS alone wouldn't give the resolution and responsiveness required. It doesn't seem to be CV-based either, since there's often no line of sight of the tracking device. Perhaps the tripod has two directional signal strength sensors so it can tell if the beacon is to the left or right, and move in order to keep the beacon centered.
The popular theory is that it's a RTK differential GPS system: base station in the tripod transmitting correction information to the remote unit. The explains the warmup time, the accuracy, as well as the big price tag.
Ha! I found your question a couple months ago after youtube hit me with the soloshot ad, and I couldn't figure out how it worked. Despite being downvoted, it still ranks fairly high on the SERP for "how the hell does the soloshot work, their site is useless".
This is by requirement line of sight. So indeed a cheap radio frequency tracker should be able to do the job. There are just minor issues with multipath and transmitter power.
EDIT: The included antenna is a wifi-like omnidirectional antenna, so I guess it's just using GPS. The precision is greatly improved due to large distances (linear precision is amplified into angular precision by O(distance) )
