Santa Zulg already abided, so it's not about anything there.
I just want to know your* personal view of a special form that
IS within one of the foci.
(And no I've never had a quest form so I'm not reaching for
any sort of advantage)

I'd figure a touch more mana cost, but not significant as with
something outside of both foci.

Or maybe power related. I'm sure some 'quest forms' are pretty
close to copies of existing forms and it is more a cosmetic
change for the 'cool factor'. So maybe those don't cost as much
extra mana. Just my two dollars** there.

*Your=anybody 'your'
**Inflation you know.