Has anyone built Moteino that scans all the networks for available data?
You can turn on Promiscuous mode to receive data from all nodes on 1 network. To receive on all networks you'd have to modify the library to make the network byte in the packet header not be part of the SYN. I'm not going to go into the detail of that here because it's a very niche requirement, you are welcome to fork the lib and make the code changes.
What Felix didn't mention in his post is that moving the Network ID out of the SYN field then reduces your actual number of 'networks' to 1. And you'll need SW filtering to separate traffic between 'pseudo' networks, because the radio won't do the filtering for you any more.
Tom