Found an interesting eBay find relavent to our discussion...
Burton Feelgood Est Women's Snowboard 140cm w Burton C60 Est Bindings Snow NR | eBay
It's a Womens Burton Feelgood 140cm with C60 bindings on it. That's a board designed for a 105 pound girl, with bindings designed for a 170 pound man. It obviously "worked" for her but you can't tell me that it was anywhere close to ideal.
It's like putting race tires on a pinto. Sure you CAN do it, but you've past the point of diminishing gains long ago.
It DOES make sense to try to match your gear.
I think you are taking it to the extreme. Obviously that is not an ideal set up. I think the message Alka is trying to convey is binding stiffness is largely user preference.
For instance for a Burton Custom board, you can ride it with Cobra Sharks, Customs, Missions, Cartels, Malavitas, etc. I think most of us could agree that any of those bindings would for the most part pair with the Custom. It's up to the user to decide the best binding with the features, stiffness, and price point.