Well, I measured the incremental valve lift versus pushrod movement in detail on a stock head and stock shaft position (675 head), and the rocker ratio did indeed increase as you approached the max lift. The rocker pad rolled/scrubbed across the tip and moved further out on the valve tip with higher lift. Just reciting some actual data; I am not convinced that it does as you think if adjusted as you described, but I'll admit that I have not checked it that way. How it contacts the tip depends heavily on the shape (curvature) of the rocker pad; the flatter the curvature, the more quickly the contact point is going to walk towards the exhaust side of the valve tip, regardless of the shaft location.
