Hello Piotr,
I had been overriding those values with the ones specified in my original post, but recently found an issue that caused audio to be rerouted to the earpiece if using StopRecording when nothing was spoken. I assume because an error was being thrown with a slight delay which probably re-reset the audio after I had manually set it.
Any chance I could grab the source for iOS in order to modify it with the ones I need to use?