I'm not sure what you mean by a dedicated p2p network. Steem Engine streams the whole blockchain right? I'm saying if all you want is a subset of data from a subset of custom_jsons, the right plug in would let you do that without the whole chain. The plug in would only need to be implemented once, then anyone (i.e. non-C++ devs) could use it. In fact Steem Engine could use it too.