Bevel only on convex or concave edges? (both shader and modifier)

Support Materials and Textures
1

I was wondering if there was a way for both bevels via geometry modifiers and the bevel shader node to only round off convex OR concave edges. Ideally there should be separate values for concave and convex bevel size.

For the bevel shader I’ve tried masking it with an AO node, but in some cases that cuts off the bevel in the wrong places.

2

I’d perosnally problably use vertex groups to control the effect with the modifier.