How often does the firestick need to be updated ?
I don't think I need to bother about that since amazon itself downloads update in background when TV is on and will install update on next restart or so.
I also found that when I use the remote to turn off the TV, it actually just turns off the screen. This helps in quick start as it just turns on the TV and doesn't need to load the OS. Even when TV is off (not from mains though), it is connected to WiFi.