I’d like to see it with SDFs!
Please elaborate. Are you thinking of approximating the distance function with an algebraic expression, with algebra itself being the "programming language"?
These can be treated as parameterised nodes in a tree, similar to what's happening here. It follows that there may be a possible adaptation of this to SDF composition, such that you can give it a shape and have it produce the SDF nodes + composition required to produce that shape.
Most existing approaches to SDFs with NNs have the NN itself take on the role of the SDF (i.e. given a point, it predicts the distance), so there's a compelling opportunity here to build a system that can produce spatial representations from existing imagery without NN inference at render-time.
I imagine adding the third dimension to the problem makes it much harder, though! I'll have to give the paper a read to determine how coupled to 2D their current approach is.