I am going to disagree with one point in your post, Dave....

ENV is not the same as CCE.   CCE relates to the chemical effectiveness of neutralizing soil pH.  ENV also takes into account the physical properties of the liming material - how fine it is ground.

This article suggests the relationship between the two as:

Example for a common method for calculating ENV:

ENV= CCE * [(A/100)*0.5 + (B/100)]

Where:

A = % particles that pass through a 8-60 mesh size

B = % particles that pass through a 60 mesh screen

I don't know if other sources use a different way to determine ENV.