Although my area is not a center of logging activity, it has been my experience that saw logs around here are bought and sold on the Doyle Scale. Commercial mills buy most of the saw logs and they use Doyle so it becomes the 'de facto' standard. I use the International 1/4" scale as a starting point for estimating the yield I might get from milling with a narrow-kerf bandsaw (+ 10%).
For 'prime' sized logs, say 16-28", Doyle and International 1/4" are almost the same. Smaller logs, and to some extent extra large ones, are more difficult and time consuming to handle for the amount of material they yield so Doyle 'discounts' smaller logs by shorting the footage.
If I were using different equipment I might consider using a different scale for predicting what I could get from a log. In addition to assuming a 1/4" kerf on the International 1/4" Scale, it also assumes all 1" lumber. If I were producing a different product, e.g.; turning stock, pen blanks, closet lining, beams, etc.; I would need to adjust the scale, or use a different scale.
Regardless of the end use, or processing method, using a consistent method like the Doyle Scale establishes an accepted method for determining the 'quantity' of wood in a saw log. What the buyer and seller agree on per-board-foot, establishes the value of those logs.