If you are changing meds and the psychiatrist is on board I don't think you will have any trouble.

My dad is a retired pharmacist, my brother and sister in law are both pharmacist, and I have a good friend who is a pharmacist. They are much more focused on opiates. I have never heard them mention stimulants but of course that can be a problem. My brother is even on a board that focuses on opiates. If a pharmacy focuses on a patient it is because they think he is doctor shopping. Like having three different docs prescribing the same thing. They may call different pharmacies or call the docs to see if they are aware of it. Or if they notice anomalies with a certain doctor they may do something or refuse to fill it. That doctor would have patterns with other patients. My brother has told me that it is usually quite obvious what is going on and there are patterns.

I think you are fine.