A question was asked today on the newbie channel which did not receive an immortal response but rather several players chimed in their opinions but were unable to provide substantiated immortal comment. I would appreciate if an immortal could please clarify:

Does the % of learning for a spell/supplication effect the effectiveness/duration of the resulting buff, debuff? (or potential for damage if the spell/supplication does damage)

As an example:

Beyond not losing concentration if I cast blindness on an opponent will having the spell at 50% or 100% effect the likelihood it succeeds? Will it effect the duration of the resulting malediction?

The players answering on the newbie channel were very much convinced the % of the ability has no such effect. It only qualifies the user for edges to learn a spell, or reveals knowledge of a resulting ability (assassin kicks, invokers etc) However even if this is true in most cases, I believe there are exceptions to this concept. Haven % learned as an example effecting the duration of Sanctuary.

Are there other such circumstances even if in general this is not the case?