Using the method you described above isn't ideal in my books, because factors such as groove modulation, stylus cut & drag, are not taken into account. And not only that, over the years I've witnessed this method, the same stylus/carts can act unpredictably depending on the LP used, some shoot in, others out. I've even had certain carts that - by virtue of using this method - required full AS to be applied, yet they still wanted to shoot in at an alarming rate. If AS is max'd out, based on the above method - which I've witnessed - it has always offset the cartridge during play, visually and sonically.
Again, any skewing / miss-alignment of the cantilever in relation to groove is THEE primary concern. Cartridges setups using a flat disk tend to dismiss that requirement outright. Rega's, in particular, with magnetic bias, tend to offset certain stylus/cants with even moderate AS applied. Actually, this is the biggest mistake I see with Rega setups, too much AS is applied and therefore ... a skewed cart.
When I setup a cartridge on a Rega, that sliding AS knob becomes a bit of a God send ... because it a rather easy to adjust on the fly ... so I visually align the AS/stylus/cantilever/groove while playing.
tb1