MQTT Subscribe/Publish Client in a strategy

Has any though of developing this to be used on an R1/R2. I have a real need to do this, to connect a number of remote site PAC-EBs to a central R2. I may need to use a cellular router instead of a direct internet connection.

Yes, thought has been given to it.
Mary and I got a super simple fixed value message sent via a comm handle, so conceptually, you could write your own basic MQTT charts.
It is not something I can share, as it was all Marys code, I just spun up the broker and helped test it.

That said, it sounds like you just need some peer-to-peer functionality. There are plenty of opto commands to do just that, mmp, transmit compressed table and streaming for example. There are more than a few forum posts on peer-to-peer that might get you started.