http://www.audiomisc.co.uk/HFN/LP3/aroundthebend.html
"Overall, the above tells us that if we wish to be able to play real-world LPs without mistracking we really need a tip mass of around half a milligram or less, and a minor radius of curvature (or equivalent) of around 3-4 microns or less."
But;
"So although theory tells us wed need to cope with 6000g and very tight curves to obtain a 0dB 20kHz test tone, the reality seems to be that practical LPs of music dont normally have modulations which reach such extreme levels. This agrees with the results in the previous article and explains the difference between the theoretical requirements and reality!"
.. and even this article is somewhat biased and old. Not to mention the fact that you
did mention tip mass as well. Thus, it is clearly not down to the shape only, as I've been saying all the time.
Nobody is claiming that advanced styli profile don't bring advantages in tracking - they do. Just how much, is another question. The recommendation of AT440MLa to avoid distortion is only half good. Yes, the diamond is small enough for most modulations at the end of the side, but then again the cantilever material is such that it resonates 13-16khz range and creates distortion. The same is true for the stylus guard and whole plastic construction of the cartridge. The cart can be dampened or loaded differently to some extent, and while it might tame some shrillness, it doesn't solve the actual problems.
Much much better option is the AT 150MLX which has gold plate boron cantilever. Boron's resonance is much higher (outside audible frequency range), and the manufacturer even claims the gold plating dampens the cantilever further.
I'm sorry but it just makes me see red people writing about vinyl playback distortion and claiming the whole culprit being about stylus shape only. It is simply not true. The only true thing in that is the fact that better stylus shapes trace high frequencies better. But it is only a small part (albeit important!) of the equation when attempting to remove distortion in vinyl playback.