How to enhance the scales?

[WTFantastico]

I'm playing Gaiden, and I only knew that this was an option from the achievement list. I read that you're meant to press "Y" or "Triangle" on the controller in the Libra menu, but that doesn't accomplish anything at all. I have all 10 pans and have already beaten the game, so... what's the secret? Why can't I upgrade the pans? Why does it feel like absolutely nobody even realizes it's possible?

[VertVentus]

In Gaiden's Rispadar, to the left of the save crystal, should be a few trees. Destroying those trees leads to safe room with the Lady of the Lake. She'll upgrade your Scale Pans when you reach the 11th layer.