The Learned Magicians' hedge magic tration has a power that allows to diminish the penalties created by Divine and Infernal Auras to magic (and likely, faerie as well) powers by means of special charms and mulets. DO you think it might be possible to integrate this ability in Hermetic magi and if so, how (likely it would be a Major Breakthrough) ??
This is of course a saga-dependant thing. In terms of the RAW, I believe it is a Major. If I were the storyguide, I won't allow it, period. I can see a tradition of Holy Magic, but not a technical use of charms and amulets. I think it cheapens the Divine.
I certainly would allow it as a major breakthrough resulting in access to that major virtue. It does not seem to violate a limit of magic - but as SG I might hold back any heavenly support for obviously evil acts.
In terms of game balance, it is pretty helpful, but every use of the ability means a stress roll in a non-magical aura (leading to additional botch dices) - as sure way to accelerated warping.
Alexios ex Miscellanea
Of course, you know that there are lots of examples of people in period actually doing this sort of thing. The rules state that the Divine only supports activities that He wants to encourage and very sinful acts might not receive any leeway from the agents of the Divine, but He works in mysterious ways, so maybe one sinful act is part of His divine plan.
Wasn't part of Bonisagus's genius that he actually got rid of such prayers and entreaties from magic when creating Hermetic Magic? Integration of specific powers from hedge traditions into Hermetic Magic is one thing - you do remove much of the mysticism to get at the raw power, but here, you're talking about putting back some the dependency upon "higher" powers.
I certainly would be inflexible about enforcing the risks inherent to such entreaties on top of the usual Twilight risks. They would not get refined away through integration. Take your chances.
I find that allowing sinful acts to get done without censure removes the personal aspect from the Divine, you are reducing him to a game-mechanical element instead of a force for good (in its own way) in the setting. This is, of course, merely my personal opinion. YMMV.