50 tiles of a 100x100 grid for phoenix powered game

In no way does a process translate to network IO, so I’m not sure that can help you. How you send the data down the wire is totally outside of a tile process, or should be.

I would think the overall memory of a game would be more important than the memory of an individual tile, by adding more processes, you add more memory to the whole game.

You may have worked out a way to send the data down the wire, but again, if you are thinking each tile process would be responsible for encoding and pushing bits down the wire, I would rethink how you are utilizing processes here.