Thanks for being here!
What is the behavior of this flag? The documentation is scant, to say the least.
Thankyou for pointing out the missing documentation for excludeDeviceCommunication. We will definitely fix that. Here is the brief description:
If includeAllNetworks is set to YES and this property is set to YES, then network traffic used for communicating with devices connected via USB or Wi-Fi is excluded from the tunnel. For example, Xcode uses a network tunnel to communicate with connected development devices like iPhone, iPad and TV. The default value of this property is YES.