In my experience, IEP teams have been very happy to accept outside evals in lieu of school-based testing. The schools I've worked in typically add classroom observation, teacher reports, and record review. In my state, the submission of a comprehensive outside eval also starts the clock for a team meeting, just as completion of a school-based eval does, which then must be convened within 10 school days. Your state regs may vary.

...pronounced like the long vowel and first letter of the alphabet...