@lewm As for adjusting azimuth, I think that the only reliable way is to do it by ear. Peter Ledermann of Soundsmith has a piece on it, which seems very convincing to me.
He points out that his best cartridge, the Hyperion, often has large crosstalk differences between the channels - like 6dB or more !!! That is, the left channel might have 44dB of separation and the right channel 50dB of separation. Therefore, he says, setting for equal channel separation is a serious error.
When I read this, some years ago, I knew why I had been unable to get equal channel separation on my Koetsu, even though it was canted over by a degree or more! And sounded awful, although I was trying to convince myself that it sounded good because, well, it measured better that way.
So, now I listen for smoothness. Less harsh, less CD-like, more like I want to listen for another two hours, more like the instruments and singers that I know - the grand piano upstairs is a great reference!. I listen for clarity with vocals sung in dialect, like Scots. I listen to renaissance accompanied choral music where sopranos and viols are on the same note - Harmonia Mundi has a lot of these. Adjust for smoothness.
And aggressive strings in the high register, like Barber’s Adagio or Paert’s Fratres. I am adjusting my Epoch to the midpoint of an interval of about 5 minutes of arc - the extremes (endpoints) are obvious, after a little listening.
Consider how you would mount a stylus on a high end cartridge. You would do it optically, with magnification and crosshairs, and maybe get it within 15 degrees of arc. Maybe. Even if you’ve got a long enough line on the stylus to align to within 15 minutes, what about the way in which the point was cut relative to the shank? Is it within 15 minutes? Not easy to say, let alone QC. This last paragraph is surmise. I don't actually know, and don't know how to find out.
That leaves a lot of room for improvement, and it’s audible. And with adjustability, doable.
IMO. YMMV.