I don't agree with the statement that the potential loss of accuracy out to 500 yds. is less than 2 MOA with a scope with it's parallax set at 110-150 yds.
It depends on the scope, what magnification it's set on, and, probably the shooter's eyes.
BTW, I've never seen any shooting techniques that would eliminate the effects of parallax.
That's the bad news. The good news is that some companies, at least, will set a given scope to parallax free at whatever range(s) you'd like. And some scopes come set for longer ranges. S&B's 10X42 PM scope is set for 300 meters not 100 meters, for instance.
You can also try using the ocular to reduce parallax. I've had great results doing that with some of my Leupolds. I went from 4-5 inch groups at 300 yds. down to 2 inch groups with one of my 6X Leupolds by simply using the ocular to reduce the parallax in the scope. E
