Any of our juices in the "PG" area are designed to inform the customer that PG is in the recipe. We are dedicated to focusing on customers who suffer from PG intolerance or allergies. With that in mind, none of our juices (even in the PG area) contain more than 10% PG total. A mix that I, as a PG sufferer, have found vapeable. I do not recommend these juices to people who are allergic to PG, however, those who only suffer minor symptoms from full PG juices might be able to enjoy these without any adverse reactions, like myself.
Short answer, it has nothing to do with concentrations but rather keeping the PG ratio low while increasing selection for some of my customers.
I don't believe in selling anything that I wouldn't use/vape myself so ratios don't matter beyond the inherent benefits to PG sufferers. Great flavor and vaping experience are the two factors that get a juice from the testing area to the website.