I'm surprised to not see one online yet, I'd imagine using a framework mainboard and possibly a usb hub with some HDMI USB capture sticks. One would be done nicely with a touch screen and possibly a router board. Has anyone made anything like this or seen a similar project code?
https://us.driftinnovation.com/blogs/news/how-to-integrate-a-drift-camera-into-your-own-application
One should be able to get a framework mainboard, touch screen lcd from ALI and a 3d printed case with a could hdmi to usbc dongels and be set to live stream with over 20 cameras! The drift Camera up to 11 can all connect to a wifi network and this software handles the obss linkage as well.