Disagree on the 'parallel arm tube' method.
Ultimately, SRA, not VTA, is the final arbiter for tracking a groove with a stylus, and many factors other than the arm tube influence SRA (angle that the cantilever exits the cart body, cantilever compliance and length, stylus shape, attachment of stylus to cant, etc.) I use a 30x magnifier, and my 'Littlelight' as a backlight, to initially set the SRA as closely as I can to 0 degrees (at 90 degrees to the record). I usually find that slightly raising the back of the arm provides the best sound, but my VPI 12.5 arm (like your 10.5) makes it easy to document repeatable settings.
I do agree, though, about making your settings on an 'average' thickness LP, finding a sweet spot, and then just playing some music-setting VTA for all records is way, way beyond my fussiness threshold, and borders on putting a premium on hi-fi effects, not on the music. IMO, of course.
Ultimately, SRA, not VTA, is the final arbiter for tracking a groove with a stylus, and many factors other than the arm tube influence SRA (angle that the cantilever exits the cart body, cantilever compliance and length, stylus shape, attachment of stylus to cant, etc.) I use a 30x magnifier, and my 'Littlelight' as a backlight, to initially set the SRA as closely as I can to 0 degrees (at 90 degrees to the record). I usually find that slightly raising the back of the arm provides the best sound, but my VPI 12.5 arm (like your 10.5) makes it easy to document repeatable settings.
I do agree, though, about making your settings on an 'average' thickness LP, finding a sweet spot, and then just playing some music-setting VTA for all records is way, way beyond my fussiness threshold, and borders on putting a premium on hi-fi effects, not on the music. IMO, of course.