I’d like to know as well…
A thought: Is it possible to expose caustic effects to the Light Path node? That way users could come up with node-based “fake” caustic lighting on the object that gets hit by the caustic.
Also, is it possible to make light-portals for caustics? The trouble with caustics is that they’re hard to sample, so what if instead of trying to make them sample faster, we give users a way to hint at where to look? I don’t know if this is doable, just my two cents.
First part, I guess no.
Second part could be a cool idea. Thinking further: a material option could turn on a special ‘caustic’ treatment where the user sets which light(s) should be looked for samples. A sort of ‘concentrate the efforts on this’