Sorry, I don't buy it. You do what you want, I'll do what I want. According to you, this is the same transfer case as my Jeep has and it's full time auto, there is no 2wd option and it's not AWD, and Jeeps aren't dying left and right from it.
Even if it does fail, it's a warranty issue. The owner's manual makes no statement about leaving it in auto being a bad thing. If it was it would be mentioned as a condition which would not be covered under warranty like they do with many other things.
I also read that Police vehicles are required to remain in auto mode at all times.
I don't buy snake oil. Show me proof that full time auto mode is bad and will cause a failure in under 200,000 miles (which is the expected life of our vehicles), or else it's just conjecture. I don't care if it will fail at 400,000 miles...