It was an upper boundary estimation, really. Different estimations can be made. For example, we could go with "max out favored charms and abilities". I'll make several different calcs in the next several hours and by the end of the day.I personally don't mind a slow-ish progression, though I think @Yog's proposal might be too slow.
I welcome all proposals, because yeah, the math can be worked in several ways.
I just wanted to work something out and save @DragonParadox the trouble.