Request to understand Xcode environment variable IDEPreferLogStreaming in Swift app dev

What does IDEPreferLogStreaming variable actually toggle on or off? Some particular logging mechanism in Xcode? Something in LLDB? Something in SwiftUI or Swift? Something in the underlaying OS such as the log command found in the Darwin shell? …

While adding IDEPreferLogStreaming=YES does resolve a error message "Logging Error: Failed to initialize logging system.", what was actually being switched on & initialized?

And, is there a use case for IDEPreferLogStreaming=NO?

I also asked about this variable's role on StackOverflow: "What is the definition and action of Xcode scheme environment variable IDEPreferLogStreaming?". However, at this time a definitive answer as to the underlaying action/mechanism has not yet been provided.