Doug,
I don't disagree that it looks naff, but what is your point?
You said
Who cares? Do we play records with an armtube? Adjust what matters. Ignore the rest.
We play records with a stylus, so as you noted the ideal method for visually estimating SRA is to set the stylus with a magnifier. That's quite the bother however and as fine tuning must follow by ear I agree it's rarely worth the fuss.
So, what do you do?
Whack the arm on any old how? Then start fussing?
The point is to get a basis for adjustment. What's wrong with that? What exactly do you use as a basis for adjustment with other arms? Maybe the edges of arms with parallel tubes? What's the difference?
I have no axe to grind but I detect that you dislike SME for some reason, which, as I am curious, is a reason for my intrusion.