As others have stated, whatever you set it at you'll have to check to make sure the arrow doesn't "porpoise -- tail up and down". The bare shaft test or paper-tuning for me at 8', shoulder level through tight newsprint with target butt 2 arrow lengths behind.
Often times when someone says their broadheads (if same weight as field points) hit higher or lower (plane) than their field points, they haven't tuned the porpoising out of their set-up.
The "book" on recurve shooting with fingers is to start 1/2" above horizontal (using a bowsquare). In fact, I start all mine at 1/2" and that is exactly where I leave it on most of my bows.
However, I know some folks who want their point of aim to be 20 yards who will contrive a set-up to produce just that. One fellow, who shoots 3-fingers under (as do I), places his nock locator 3/4" high and uses a full-length arrow (about 3 inches longer than he needs). This combo allows him to see the point of his arrow on the exact spot he wants to hit at 20 yards. Then he adjusts his aim point at shorter and longer distances. Obviously, this fellow isn't an instinctive shooter. He does this for 3-D competitions that require that his finger touch his arrow nock on every shot (can't string walk.