Here's the latest test run, this time using cones for the course markers. It does two successful laps before missing a turn. It would appear that the guidance has the most trouble with sharp turns, particularly if that results in it approaching a wall at a near-perpendicular angle. Future improvements will hopefully address this problem.
P.S. If the video plays absurdly fast, just restart it. Some browsers seem to have an issue with the video playback.
P.P.S. If you're wondering at the three-month gap in posting, I've been finishing my Master's thesis, and have only recently reemerged into the sunlit world.