That nutrient chart is "the gold standard" of gardening and has been around for decades.
As an example of macro availability, if you look closely at the N range you'll notice that N is readily available from a pH of 5.0 to 9.0, which corroborates with what I have been saying for years - cannabis is very pH tolerant when it comes to availability, lockouts. Most lockouts are caused by the use, abuse if you will, of NPK ratios that are way out of wack
as it pertains to plant requirements, like your typical cannabis specific Grow foods that use a much higher ratio of K than N. They get 'em bass ackwards all the time.
Being that the grower's lower leaves are yellowing (and will soon drop), my best guess is that he is using a food that is not providing enough N, OR, has a cultural problem which is compromising the root system such that it is not capable of proper salts uptake - same thing, same visual affect.
Tooler, what are the NPK values of the foods you are using, and/or recently changed to?
Have a good one,
UB