As
@ewoodrick said (and I also mentioned in the post you quoted), Traditional dealers never "forgive" mileage. They take the cost it would cost you out of the deal somewhere else. They either buy the car at a lower price than they otherwise would have (and use part of that profit to pay for the mileage), or bury the money the mileage cost into the cost of the new car deal.
There is no circumstance in which they simply "eat" it or "hand wave" it away. You still pay it, but if you dont know how traditional dealers function you may not realize you were paying it.
Same thing with "I had damages on my lease turn in but the dealer didnt charge me for them". The more things "the dealer didnt charge for" on your previous lease returns, the worse your deal on the new car you got was.