eric on another forum came up with what I consider the answer I was looking for.....

"You are correct that it doesn't change seat-to-seat duration at the valve, but once the valve is off the seat the larger rocker ratio has the valve meeting any given lift point sooner on the opening side of the lobe, and later on the closing side of the lobe than a smaller ratio.

This is a rough approximate example, not real numbers at all, just for illustration purposes....but think about it this way..... Getting the valve open to .200" lift with 1.5 rockers might take 30° of crank rotation to achieve, but the 1.6 rocker gets the valve to .200" lift in 28° crank rotation....at 30° the 1.6 rocker has the valve open .213".....

The "apparent" or "virtual" is the fact that airflow only knows what the valve is doing because the valve is the "door" to the combustion chamber., and not what the lifter is doing.

This difference is because we measure the cam at the cam, where as the airflow "measures" the cam at the valve..... Does that help you with visualizing how a larger rocker ratio can have the same effect as adding duration to the cam lobe??"

My reply to him:
To say that it has the EFFECT of increasing the duration slightly makes perfect sense eric, but I will still be correcting those who say flatly that it increases the duration of the camshaft. Black and white. Two different things.
Thanks to you and thanks to bogie.

.