My final settings are done by ear, using a couple of well-known (at least to me) records including the well known flying fish record about which there is an article for using that record to set VTA. There are other records as well: I first heard that Clements/Holland, Norman Blake and Tut Taylor record in a listening session decades ago, and Saurerkraut 'n Solar Energy was a killer then.
But, using it to set VTA is for me, like a knife edge, and gets closer to the zone where you have to adjust for differences in sound, quicker.
Once I'm dialed in, I don't change much- if it is a stupidly fat record, I'll take account of it, but I'm not down to adjusting per record. I also found that the need to do so varies by cartridge; that is, certain cartridges will sound better if dialed in more to whatever is happening in the grooves.
But, using it to set VTA is for me, like a knife edge, and gets closer to the zone where you have to adjust for differences in sound, quicker.
Once I'm dialed in, I don't change much- if it is a stupidly fat record, I'll take account of it, but I'm not down to adjusting per record. I also found that the need to do so varies by cartridge; that is, certain cartridges will sound better if dialed in more to whatever is happening in the grooves.