Re: Whoa, hang on
@sgt_Oddball - you seem to have missed the joke icon (i hope)
A subnet is not enough. The tern "Air gaped" is there for a reason, although in the days of bluetooth and WiFi, the concept is harder to achieve than ever.
A different subnet is nowhere near enough separation for something like that. Even if connectivity was required between the different domains - and I can't really see any need for that. Displaying the location and speed is just eye candy, i'd hate to think that someone took the decision of eye candy over safety and security.
Don't forget that proper separation requires additional hardware to sanitise the content and all of this shiny kit adds weight to the planes which increases running costs / maintenance.