I found that the original design didn't lock as securely as I hoped. It is also kind of difficult to find the right place where it locks.
I change the teeth profile on the legs and locking screw to have deeper grooves and thicker teeth. It now centers better and locks more securely. However, the number of ‘stops’ where the legs can lock is decreased as the teeth are larger. I don't find this to be a problem, though.
Another thing I notice is that the orientation of the legs when assembling is important. The part with more teeth need to face outward for the lock mechanism to be effective.
Printed mine in PolyTerra PLA with 0.3mm layer height, 4 perimeters, and 10% infill.
I also included step files if you want to play with the profile.
Hope this is useful!
The author remixed this model.