They do have physical dual SIM for certain markets. Ex: China
I specifically searched for and bought the physical dual SIM version of the iPhone 11 Pro, because most of the MVNOs here still don't support eSIM.
If I used it with any regularity, I could probably work around it with a keyboard shortcut.
I have nothing that links to Hong Kong or China, so it's probably implemented by identifying the different phone model number of the dual SIM iPhone.