New owner here - are there any settings to control how quickly sleep mode kicks in or to disable it entirely when usb externally powered? Perfect example of needing this would be using the Nexus 7 as a car gps.
Problem with that is you can't prevent it from sleeping. The maximum amount of minutes to delay sleep is 30. I think the Developer options method is the only way to keep it awake unless you have an app open that has the ability to keep the device awake as well.
I don't think the N7 would sleep when using it as a GPS, but I could be wrong. Wouldn't it be the same thing as watching a movie? As long as it's running, it would not sleep.