The problem is twofold, overhang changes with arm height and SRA varies from 91 to 95 degrees. Even Jon Risch* (the guy whose work this is based on) said that 91 degrees is right for 80% of all records. In reality, I think most people who occasionally change arm height for a record, usually change it a small amount. A 9" arm requires 4mm height adjustment for 1 degree change. Who set up the alternatives of changing for every record, or not at all?
If you use a Loefgren A or B alignment set at 92 degrees, then raising your arm slightly won't do much to alignment. Any two set of nulls between 60 and 121 mm, is a "good" alignment. Look at the nulls for Loefgren A, B, and Stevenson. If you're skeptical, get a straight line calibrated grid, raise your arm 2 mm and see where the nulls are. IMO SRA errors can be much more audible. Some people don't seem to hear it, but some people are nearly oblivious to speed variations.
Put a UHQR on your table, and in order to maintain your orig alignment the arm must be raised the same amount of extra record thickness. Look at the record and arm pillar as 2 sides of a right triangle. The arm tube to stylus is the hypotenuse. The alignment change is very small and SRA goes negative, Sound a little bassy?
*Audio magazine March 1981