And that if one day it does end up before a judge, the stack of letters will show how reasonable you were and how ridiculous they were. Sometimes when they realize what you are doing they suddenly become more flexible.
Meaning you sue them?
In that case, the most important thing is the name of the judge.
Well, I am just sharing what Pete Wright has in his books and workshops--and since he argued and won a case before the Supreme Court I figure he knows what he is talking about1 And not actually sueing them--due process or something? My point is by doing what he suggests it is less likely to end up in front of a judge.
Edited to add: just saw your edit--and yes--that is the point--the sheer volume of evidence showing the parent did everything possible to get their child an appropriate education in a reasonable way becomes hard to find against.
