Of course you say that mere minutes after I sent my email.
It will be an ongoing discussion, I just have a feeling.
(And apologies for totally missing the reference of "convoluted", earlier - I was thinking of... well, of nothing very clearly, I guess. 
)
Who, me? 
Sorry, I was focused on another thread or two. My bad. 
Chris
Just consider yourself lucky it wasn't a crosspost. 8)
If the MuVi can be cast anytime during the ritual, it could be cast at the last moment. And holding Concentration for 1-2 hours while doing a ritual is not for the sane at heart.
I think the penetrate the penetration rule is pretty elegant. You never have to worry about an enemy pink dotting your spells with MuVi.
On the downside that's a new mechanic - and "errata" (usually) doesn't introduce new mechanics unless they were accidentally omitted.
On the plus side, it is not at all complex or confusing, and it does have an attractive logic to it, a coherence that works on multiple levels.
And if it's something that is going to be "fixed", it should be fixed right. (And by "right" I mean to optimize the opportunity to make changes, rather than clarify unsatisfactory rules and then have more favorable listed separately.)
+1.
But IIRC, penetration of the MuVi spellvs penetration of the modified spell to be is canon in sorcerer fork and mirror of opposition.
Edit: it's not there, it's in the MuVi box, last paragraph first colomn.
I just looked quickly and I didn't see it in those spells.
The enemy has to penetrate your parma to MuVi your spells so pink dotting is an atypical event. In order for it to matter their penetration must be between your magic resistance and theirs and your spell must have higher penetration than their resistance.
Erik, I found it. It's in the MutoVim box. Last paragraph of first column.
huh, would you look at that. Well then, I guess it's not a change at all.
Have we talked about the Muto Vim to transforms Infernal powers on other things? I can read that No hermetic spells can be affected... then?
I'm still thinking about what I want to do about this. How about this suggestion:
Muto Vim spells work by altering the magical energies that create the spell as it is being cast. The spell is the result of the combination of the base casting and the Muto Vim effect, and has its effect once both the casting and the Muto Vim effect have finished. This means that a Muto Vim spell must have a duration at least as long as the casting of the target spell, but need not last for as long as the spell itself. For normally-cast formulaic spells, a Momentary Duration is sufficient, but if the casting time is longer for any reason, the Muto Vim spell must also have a longer Duration; Sun is sufficient for any practical Ritual.
I'm not sure that's quite thorough enough, but Vim really needs a complete overhaul.
This makes sense. Works for me.
...and wouldn't I love to have my fingers in that
I like that very much. (although IIRC -I just skimmed all of the line's muto vim spells last night- there is a spell from ancient magic for use after the caster has unlocked the secrets of Grigori magic that changes the sort of vis required for a spell and it is duration momentary)
Sounds good to me.
I would say it wouldn't be hard to issue errata for one or two problematic spells. That spell would need to be altered anyway using the current rules for a non-momentary ritual. So it's not like things are changing much vis-a-vis that spell.
Chris
I'm not a fan mostly because Wizard's Communion still get's screwed with. That can either be re-figured as a lower base effect to accommodate a greater duration or kept as is under the tried and true "doesn't follow the rules because it's an old Mercurian ritual". I could even see a custom duration called "Ritual" that is equivalent to diameter/concentration.
Does it really get messed up? Wizard's Communion can be used for non-ritual spell casting. In my experience, that's where it has been used the most since it allows a team, given a small extra bit of time, to give a nice boost to the penetration of a powerful spell. Meanwhile, many rituals don't need penetration (E.g. typical healing, stat boosting, and (depending on interpretation) Aegis of the Hearth). Also, generally speaking, though more tiring and requiring more time, ritual spell casting is easier than formulaic spell casting because you get to add both Artes Liberales and Philosophiae to your roll.
If you want to use it on rituals, just make a different version with D: Sun or (with more risk) D: Concentration. No big deal.
Chris
It's more of a history thing. In the in-game history as well as the out-of-game history WC has always been closely related to ritual casting. It seems to come from the Cult of Mercury Cooperative casting practices, and is a special ability of Mercurian Hermetics the go-to guys for ritual casting. If a Canonical change is made to MuVi then I would like to see the default WC stay consistent with that background.