Unbelievable how the cantilever vibrated back and forth with incorrect AS but once AS was set no back and forth movement of the cantilever assembly.
For how long? For the length of the side? I doubt it very much. Mr. Boisclair may have demonstrated a short segment where AS was optimized but barring one of the tonearm designs referenced above or the like, optimum AS does not exist for very long. The concept is similar to null points and alignment. And for good reason.
And guess what? Cantilevers are designed to vibrate. Suspensions and motor assemblies are designed around real world conditions. Compared to surface contaminants, imperfect pressings, EMI/RFI, alignment compromises, limited stereo separation, signal to noise ratio limitations, wow, rumble, flutter, speed and so much more, you're at some point losing the forest for the trees.
So as I said, AS is important but so are many other aspects of cartridge set-up. And as I said, more damage can be done by employing too much AS than by using none. This is similar to the concept that more damage can be done by setting VTF too low than too high, assuming you are still within a reasonable range of optimum.
Eventually every stylus tip is going to need replacement. And, where is the scientific data as to the extent of right channel premature wear when not using AS?
Forgive me for straying towards the pragmatic. The real world. How many times have you picked up a used record and been amazed that it sounds better than many/most of your new pressings? Do you really think that the previous owner(s) had their AS dialed in?