The wishing they weren't a specialist is so real. I wish my psychiatrist was also my GP and my therapist. I've found out through her about diagnoses that are in my chart that nobody ever bothered to tell me about and that I overlooked in there, as well as about off label medication uses that you mentioned and medication or illness interactions I never would've guessed. Outside her domain too, e.g. between my thyroid meds and ibuprofen. All the GPs I've ever been to are either jaded, refuse to learn or admit you might know something they dont, or don't take you seriously.