It's doable already but we don't have any pre-made node in SD that will get you there automatically just yet. You would need to create a function in a transformation node to "zoom in" on one of the tiles in your texture and use 16 of them with different coordinates, pack this in a subgraph to make it all nice and easy to…
I've started creating some multi-image textures (for example, a 4x4 set of 16 textures crammed into 1 UV set) to use in UE4 particle systems. I'd also like to use them in Substance Designer, maybe as input to a Scatter node. For UE4 particle systems, this is pretty easy, using the SubUV feature. Does SD support something…