.....................doesn't Saturn sometimes give great wealth and power to nativities, and doesn't he sometimes cause great afflictions? Yes, of course, but that has to do with his harmonious or disharmonious relationship with the planet/angle/lot through the different aspects and natures of the subjects. So combining essential and accidental dignity into the same concept does not prevent us from making these distinctions, while I would argue that too much emphasis on the essential dignity could prevent someone making this distinction in the particular cases - for example when it helps rank with trine to the Sun from Aquarius by day, but causes divorce with square to the Moon in a dual sign in a male nativity, Aquarius is not going to help the first and mitigate the latter, I argue that is going to increase and actualize the effects of both.
Powerful Saturn at the nativity does not mean that it will give only very good or very evil at all times (though it certainly can exceed in one direction), if you use the recasting of horoscopes at solar and lunar revolutions, planets change their powers, which allows for differentiation in the chronocratorship. You can't make this important differentiation if you only use primary directions, profections or what have you with the nativity though.