Following up, I have done some more experimenting with azimuth setting and found some interesting results. I apologize ahead of time if I send someone off spending hours on this tweak, but it shouldn't take that long, and the final result (at least for me) was remarkable.
I lived with the azimuth set up with the test record and oscilloscope for a week or more, but it gradually began to bother me that the sound stage (and voice) was offset to the left and that there was a slight 'scratchiness' to peripheral instruments. I decided I would try to set the azimuth again, and I tried it once by the same technique as above, with no better result. I then decided that, although I must be very close with the above method, I might be better off making the final changes by ear. I put on a familiar, complex stereo LP with vocals and instruments, made 2-3 MINIMAL changes (no more than just a few degrees) surrounding the initial location found by the above method, and suddenly everything clicked into place. The singer was dead-center, sound stage was much better, and the scratchiness in the instruments in the periphery was gone.
You might say this was just a fluke, but it's the second time I have achieved such a result by ear (the first time I thought I could do better and messed it up), and those are the only two times the turntable and cartridge have sounded 'right'. I should say that before the final setting of the azimuth by ear, I had optimized everything else, including VTF/VTA (also by ear), and zero anti-skate.
Just remember to approximate the correct azimuth first with something like a test record and oscilloscope and only change the azimuth a few degrees at a time (about as little as you can possibly change it). Just a few degrees will make a huge difference.
I've lived with this azimuth setting for about a week now, and it still sounds perfect to my ears (on par with a similar turntable set up properly in a high-end audio store). As "the enemy of good is better", I don't intend to make any further changes anytime soon.