Not a switch - a bus. A message bus. All devices are interconnected through a message bus so any device can listen to messages on the bus or can publish messages that other devices can listen to. Full cycle supports this for very flexible deployment strategies that scale.
The miner stats and sensor readings are broadcast on the bus so you can do anything you want with them. Display on screen, push to cloud, etc. The Raspberry Pi with LCD touch screen is just an entry level starting point for a small size farm.
Software components to extend and customize the controller can be written in any language that can talk to the bus. Python, Javascript, PHP, Go, ...
How difficult would it be to;
Let's say, hooking up 5 GPU based mining rigs with a RPi and display the stats on a mini display
Versus, hooking the same setup with 5 Asic miners?
And can you teach me? How much would it cost? PM me the details.