(We need an "Edit Message" by George! 
)
Okay, before it's cited, I just read nudel's HOW TO: Understand and Configure Folder Formats thread. (Wonderful FAQ!)
It didn't answer my question, but coincidentally, I discovered how to quickly apply a favorite format. (It's already defined on the default toolbar. Duh. )
But before I go, I would like verification that there is really no easy (easy meaning "clean") way just to toggle the format custom hidden filters on and off as I describe in my original post. Thanks!