Noted the upper bearing shedding a lot of PLA so another random idea was to add a washer. That instantly got it to drive a lot straighter. It still isn't perfect, but it was an amazing improvement for a washer. It might even be able to handle the neighbor's landscaping. The next step might be to try a smaller washer & silicone grease.

The washer wasn't expected to make any difference in tracking because it still has to rub against the big old pot in the lower bearing. What might have degraded tracking were the large horizontal surfaces being pressed together in the upper bearing. The lower bearing has just enough clearance to avoid rubbing, but it might use another .5mm.

Finally, the most life altering improvement was using a paperclip for farstening it to the animal. That eliminated the waist strap & made it really easy to farsten to clothing.  Just clip & unclip to feed the lion.

 It's believed integral feedback would further improve tracking. The mane problem an integral would overcome is the offset between the leash pot & the servo.  This would entail moving the feedback to a full PID controller.

The lion kingdom continually searches for a more compact retractable string, but this may be the only thing strong enough to forcibly overpower a steering failure.