I would note that the equal lift method was the Vincent Factory's method of timing a cam. That was the position where all of the gear markings were stamped for correct alignment.
I have mentioned before, it is not possible to set a cam accurately at its highest lift. This is because the point of highest lift on a cam has some similarity with the point of lowest lift; it lasts for some time. When the follower is traveling over the highest point of the cam, it usually reads that same maximum lift number for several degrees. As a result of this "dwell" at the peak, which can last as long as 7 degrees, you would be forced to select one of these spots as the place to set your cam timing.
The cam does the exact same thing at the lowest lift, which is the base circle. This is why we set the "lash" there. The base circle has a much longer dwell, which makes it very easy to find. The shortest dwell at the peak may last only 3 or 4 degrees, but which one of those 3 or 4 spots should you choose for timing?
Frankly, the cam timing can be away from the 4-degree spot and work well. Andrews cam would often recommend zero degrees with no serious ill effects. Many owners rise to the challenge of attempting more precision than may be necessary, but often rising to that challenge will usually offer the default of consistency at worst.
David