I was just adding information some people may find helpful and not responding to your post.
I don't agree with the position "to ignore all advice given by anyone unless it is from Tesla corporate directly and in writing." I believe in Rafe Mair's axiom number 1 being: "You make a serious mistake in assuming that people in charge know what the hell they’re doing." To me, this applies to all aspects of life, be it politics, corporations, or whatever else. I think Tesla is learning about batteries as they go alone, as is Nissan. Of course, they know more than most, but they don't know everything and they can be wrong. I agree it's best to follow their advice but sometimes it's difficult to find out what that advice is. So I try to get as much information as I can from various sources and vet it myself. Nissan first told us not to charge to 100% to prolong life, then they changed that position to the point that it is very difficult in recent cars to charge to under 100%.
I found what I posted above to be informative whether or not it actually comes from Tesla and readers can make what they want from it. I also find this information to be informative in understanding how lithium batteries operate, but of course it doesn't come from Tesla...
How to Prolong Lithium-based Batteries - Battery University