The Help says about the second Parameter for using stdout for FileAppend:
My guess is that it works like v1.However, text sent to stdout will not appear at the command prompt it was launched from. This can be worked around by 1) compiling the script with the Ahk2Exe ConsoleApp directive, or 2) piping a script's output to another command or program.
But using stdout ("*") as the second Parameter without changing the executable subsystem to Console mode the compiled program throws an error message in a message box saying "The handle is invalid".