My Footage Is Grainy On The Main Switching Device
Just because your footage is grainy when staring at the production screen of the main switching device does not mean that the final result will also be grainy.
The main switching device receives video from the remote cameras via WiFi and displays it on screen for you to see. The displayed video has a limited quality, far below what the cameras themselves will provide. The display allows you to mix cameras live and build your production, but it is not recorded for use. Instead, each camera records in its best quality, and the final production is built from these high-quality recordings.
This means that the final production depends neither on the main switching device nor on the WiFi connection. It only depends on the cameras. You may experience transmission problems or artifacts while mixing, but this will not appear on the final video production.