You can also design a valve train to minimize the product of scrubbing and load. That is, the arc is offset so that as the valve opens the travel across the tip is reduced.

It requires some advanced math to design it that way. I've never figured out the math but I can simulate it on a CAD system. The bottom line is that if you have the rocker arm 90 degrees to the valve at 2/3 lift. When you do it this way you have extra travel across the valve tip at low load, but reduced travel at high loads.

Some engine builders do it this way when running monster valve springs.