As I just pointed out, Hot Desking is for the user the actual phones they log into are still the station/endpoint and have their own ID so yes, regardless of what user is logged into it the station should be able to present its ID.
As for mobile phones, yeah I’m not sure. My expectation is that if I’m out and I need to call 911 from my mobile, I’m not bringing up Bria to do it. I’m just hitting the “Make Emergency Call” option or straight up dial 911.