Well you can always try the simpler things first have you changed your cabin filter and cleaned out the compartment they're bad about collecting debris and by the way that's the same compartment that you're blower motor resistor and blower motor are in. You seem pretty confident that the smell is more like brakes or electrical. I think I would discount brakes because you had just gotten in the car and had not moved it yet so the brakes were not hot, I still think the prime candidate is the blower motor resistor and or blower motor. Could be as simple as a buildup of debris. I have found on my car that I need to change the filter twice a year not because the filter gets clogged up but mainly to keep the debris cleaned out. By any chance does the carpet get wet on the passenger side in the footwell? It is possible you have a coolant leak at the heater core, antifreeze has a similar smell to brakes. Could be a number of things I'm afraid you're just going to have to take some time and run it down. Good luck keep us posted 😉