I imagine they will stick to their guns on that, seems silly since it is just a presentation. BUT, Can you bring someone...even an attorney with you? They dont have to know if it is a new person you hired or got to volunteer to come... At least see if you can get an advocate from ARC or an educational advocacy organization. If you have other witnesses along the line to your situation have them come... EACH ONE WITH A NOTEBOOK AND PEN TAKING NOTES CONSTANTLY. Doesn't matter what they write. Get introductions at the beginning of the meeting and have the people ask for how names are spelled so you have them on alert that they are being watched and heard by others.
If you can tape the meeting, then do so for sure.
Do you have a disability law center/legal aid type of place??? if you find someone who is interested (let them know this is urgent) they may actually get into this... especially newbies may think this is a good experience. Again, the board does not need to know you did this for the meeting, they can just think you have been consulting with legal folks all along (have you??).
In the mean time, how are you going to handle if they cut you off, get defensive, etc? Sounds like a long document, they are not likely to go through each detail so how are you planning to present it?
Each district needs to have a special needs advisory committee. This committee is made up of sp ed, parents, community people who are interested in Special Education and they can be a powerful voice for you too. Many parents join because of issues they have had so you tend to have "friends". If you can find your district's committee that may be another place to get support.
So sorry for your struggles but I am really impressed you are bringing your concerns to them. Hope you can find some form of back up for your presentation.