My opinion: initiate an internal transfer before the negative rating / PIP hits and hope you get a more sympathetic manager. Nitpicking about you actual performance and whether you are getting accommodations do not matter unless you are planning to litigate, a dubious strategy. Your manager does not find your contributions to be sufficient so run like hell while you still can.
I'm trying for an internal transfer and looking at external option. There aren't a lot of positions right now.
I've already talked to an employment lawyer and they said I have a good case. He said he couldn't understand why they aren't providing the accommodations because they are common and reasonable, and that they don't even seem to be engaging in the interactive process. He said it sounds like I'm being targeted. This seems to fit since my direct manager said this is being pushed by my department head for some unknown reason.