Hello,
A while ago I fiddled a bit with an offline translucency technique as discussed here: https://www.gamedev.net/topic/653094-baking-a-local-thickness-map/. Never officially made it part of the baking pipeline, even though it should only be a small extension - still just flip and ray test those normals.
Though instead of averaging all sampled ray distances, I split them up into small 4x4 8-bits precision sets, so as to break the uniform thickness up into several view dependent values. These grids snug nicely into a uint32[4] vertex map component and can be sampled in a vertex shader based on the camera-to-vertex view tangent.
Looks good, can you show what it look slik when the object has a light directly on the other side? Is there a control to define how much light is let through? based off of a thickness map?