So please, have mercy and cure my ignorance and explain what EMR means.
It's spoken about as a monolith because that's how it's sold -- there are maybe a dozen platforms in wide use (which are then usually customized by a system integrator for a big hospital). They do have every option you could possibly think of.
I'm not criticizing you here (you're not trying to do a medical startup), but anyone who is trying to do a medical startup needs to know a whole lot about EMR systems -- more specifically how they are bought and sold -- if they want to make any traction. All medical software flows through the EMR, and they are closed platforms by design.
https://healthit.ahrq.gov/key-topics/electronic-medical-reco...