I'm playing with Underground Biomes and the crystals didn't generate. I added the UB stone (and earthworks/rustic for good measure) and ran retrogen but the resonating wand didn't reveal any crystals. Do I need to move to new chunks?

Yes. As far as AS is considered, the chunks properly "generated with the current version and configurations". It just so happened that the configurations were setup wrong and thus didn't generate any ore at all.

That's what I thought. Thanks.