Yes, I should have put the "disclaimer" that the (template) is a rather general starting point AND was developed for modern rifles that don't "need" to follow the comb line of, say, a Bedford rifle etc.
I use the results of that chart to try and "wiggle in" what I can without destroying the original architecture of the rifle style I'm going for.
And yes, 3/16" - 3/8" of cast off (for a right handed shooter) would be reasonable even if you didn't know who would be shooting the rifle.
(although 3/8" is starting to become "pronounced")
I do believe it is called "cast on" if the shooter is left handed, but is calculated the same way.
Generally you work in the cast from the center of the butt plate to the nose of the comb (by moving the center of the butt plate to the right of the center line of your blank by your offset - 1/4" or whatever).
On a couple of occasions, when working with rather thin stock blanks I have carried the cast all the way to the rear most point of the tang (to allow enough wood for the cheek piece).
However, that does (bend) the wrist and would not be appropriate for higher caliber rifles or those that would shoot heavy conicals over heavy power charges (so maybe 45 cal at the max, 40 and under all the better).