Trim Tab Mounting Height theory

Quick question on the theory of mounting trim tab plate above the bottom of hull. Bennett recommends their standard tabs being mounted as close to flush, but then in full retract they are 5/8" higher in the back with respect to the bottom of the hull. On their high performance tabs, they recommend the front of the tabs being mounted 3/8" above the bottom of the hull and at full retract the aft side of the tabs is 1" higher than the projected bottom. In either case, full retract is roughly 2.9° of essentially rocker.

Question, is 3° of rocker enough to where you will actually break free from the water at normal speeds? Say 25-40knots. To me, it would seem that if the front of the tab is flush, that water wouldn't actually break free but would rather try and suck down the transom. Thoughts?