The more I get this packrat parser and Grammar.Pack method working the more I realize that having an all encompassing grammar is actually not the way to go because of the unnecessary additional overhead or packing unneeded stuff into the Grammar will have on cache hits during rule lookups.
It still makes sense, however, to allow for libraries of standalone Rules that don’t require knowing about the caching capabilities of any grammar. The rule generating helper functions will always have value for this.