[Tyrant]

In most cases, even with resource intensive nations, the answer is to build more castles and/or build one an iron mine. So as is, it's really only usefull if you have cap-only resource heavy units and/or for the rare heavy metal quick start plan. Micah's suggestion seems like the easiest fix, though the castle suggestions would be more fun.

I've strained my brain trying to think of a another thematic additional effect, and auto-PD build is the only thing i came up with. TC has that as a dominion benny, so there's some code for that already, but i dont' have any idea if would be easy to implement.