Unless someone else knows of an exception, school districts are not required to pay for an IEE provider to attend an IEP meeting. YOU may think they're not qualified to discuss that, but THEY are not going to think/say/admit that. They are going to stand by their evaluations and the staff they have to interpret them. If the school district thought they didn't have the appropriate staff "inhouse" to do a certain evaluation, they would have procured an outside evaluator to do the school eval. This is all theoretical, of course, and may not be the case in reality, but that's the position the school district is going to take.
If you really want the IEE provider to attend, here are a few things you can do to reduce the cost of having to pay him/her:
1) Have them attend via Zoom.
2) Ask the IEP team ahead of time to have them go first on the agenda so that they can leave. Or have a specific time at which they participate. That way they're not sitting through the entire meeting racking up their billable hours.
3) Pay them to write up an additional report with anything you think would be helpful to delineate or clarify from the evaluation (specifically referring to present level, IEP goals, and accommodations) which you can provide to the IEP team prior to the meeting.