So all you are going to say is 1) I'm not going to offer proof of what I'm saying and 2) What I said about leaving your car at 0% is right.There actually is proof of what I'm saying but I'll leave it to others to dig it up (hint: Jeff Dahn, BatteryMD, owner manual, . . . ). My info comes from talking directly with Tesla and other battery experts. It's also what the car tells you both in the manual and cautions that pop up when you get to a low or high SoC.
I have seen a bricked Tesla Roadster where the owner left it unplugged for a while after returning with it at low SoC. Given the loud litigious threats from his lawyer afterward, it was apparent that there may have been more involved than just lazy stupidity.
As far as buffer on top, bottom, or not at all, this is irrelevant. If only affects what the battery gauge says not what the battery SoC actually is. If the real 10% at the top and bottom are hidden (ie. in the buffer), then there won't be much of a problem leaving the car when it says zero or full. If not, then you'll do more damage to your car.
My guess would be that, if there is a buffer, it is probably set so that your car battery will last for the warranty period. Therefore, if you keep the battery between with the gauge reporting between 10% and 90% during all long time periods, it will be in even better shape after its warranty expires.
There will be little harm in fully charging before a long leg of a trip or letting it dip low on your way to charge it. Just drive away soon after it reaches 100% and charge soon after it reaches zero and you'll be fine. Doing this for over 12 years with a Tesla Roadster has worked just fine for me.
If I'm wrong, and you follow my guidance you'll have suffered the inconvenience of having to plug it in a bit more often. If I'm right and you go against my guidance, your car's value to you or others may be worth less.
Its kind of like if we are looking for a place to camp and come to a cleared area by a railroad track. I say "I don't recommend camping on the tracks since a train may come". Someone else on the internet may say "its ok, there aren't any trains coming tonight". You could heed my suggestion and pitch your tent away from the tracks and sleep fine. Or you can pitch your tent on the tracks. Following the other advice: you may be ok . . . .
Your choice, I don't care. My advice is free and others are free to listen or not.