If you had a child with 2e issues and your school were offering you testing but you could afford private testing with a neuropsych, how would you approach it? Would you worry that school might miss something important and inadvertently "block" you from getting more astute results by having to wait to access that test again?
Additionally if your child had/may have a vision issue (waiting for visit to diagnose), do you resolve that first for more accurate results or plow ahead with testing, hoping to get more diagnostic information about how much is vision and how much other issues at play?
If possible, do the vision testing first.
The thing about school and private evals is that they are after different things. If possible, I advocate letting school do their piece so that services or accommodations can be put into place if needed, but also getting the best private information you can.
School is not allowed to make medical diagnoses. They are doing an "educational eval"-- they look at academic and functional skills within the school setting. A private neuropsych is looking across all contexts, is able to make an actual diagnosis, and has a much more extensive toolkit; you will get more details from a private eval.
Depending on your district, it can also be a factor that school psychologists may be under pressure to NOT find things for budgetary reasons. This is illegal, but it happens.
DeeDee