Can you help me understand by giving some practical real-world use case how you'd need different actions for one Bluetooth device depending on what profile was in use?

I do have to say that even though I'm pretty sure you can query what profiles the device supports, I'm not at all sure yet that you have a way to know which one of those profiles are in use. And if I understood you correctly, it's the profiles that are in use currently are what you'd be interested in most.