Please excuse the winded response: Yes the android box pulls 2A @ 5V (or more if you are powering usb components off the android box). I have considered installing a small hobbyist 12V battery to supply power to the android box 24/7 and not drain the main battery but do not think I want to go through the trouble of designing an integrated 555 timer secondary charging circuit.
I have been monitoring the SAT NAV power plug that is not in use as I “planned” to tap power from that un- used plug with the female adapter pictured below. It appears that the 3 cables are ground, +12, and “sense” but sense also supplies a ground so I think that is what sends a ground “on signal” to the mmi components to power up.
However after leaving my volt meter on those pins with the car overnight under different parameters (trunk open, closed, car locked, unlocked, etc) it appears they receive constant power and there is a power supply switching module built into the MMI components themselves (CD player, nav, ami, radio, etc) that turns on the units when you activate the unlock feature on the car or press the start button to wake the car.
So given this issue I have yet to determine the best place to draw power from, to power up the android box. I have considered switched power from the passanger side trunk fuse panel, however if I shut off the car I am afraid it will immediately shut off the android box which would be a big annoyance.
So this is TBD at this time. I may open up the SAT NAV box I removed and monitor the internal power supply and see how and when it switches on and off, I may be able to steal that circuit.
In answer to your question, the android box boots within 30 seconds and is practically live once the mmi boots up so the delay is not an annoyance. I have it boot directly into dash command so the gauges are available immediately. As well auto connect to bluetooth OBD module and auto connect to my cell phone hotspot upon boot. You can also set up your cell phone to activate hotspot when it connects to a bluetooth device (MMI bluetooth phone / AMI bluetooth) with some apps from the app store.
It is not necessarily “bad” to cold shut off the android box without properly shutting it down. Does not seem to ever cause me any problems from when I had the android box in my AR w/rnse. However, there is a power button on the android screen menu bar at the bottom that you can press to shut off the android box when ever you please. I just am hoping to find some MMI power circuit that keeps our MMI systems live for a few minutes after turning off the car. Once I determine this location I will update.