Default startup variables during QGroundControl and PX4 startup

I am utilizing QGroundControl in conjunction with Gazebo in order to run PX4 UAV simulations. I am interested in determining the default startup variables during the initial startup and connection of QGroundControl with PX4. I have tried looking through the QGroundControl and PX4 source on Github, but I am unable to find any definitions of default startup variables. Any assistance in this matter would be appreciated.

No idea what you mean by default startup variables. Can you give some examples?

Are you talking about the initial parameter settings? For PX4 SITL and the Iris you can find the parameters here:

What I mean is default parameters set during the initial link between QGroundControl and PX4, such as the connection type, rate, etc.

Settings/General to turn off Autoconnect: Then Settings/Comm Links to create your own custom links to connect to.