Thanks for explaining plural; I’ll write that down.
MFi cannot provide a different microphone. Accessories can. Both Oticon and Resound have modern and fairly unobtrusive clipon units that work with all phones and have their own mic. Also resound has a mic only unit that is useful for handsfree and also noisy situations or lecture halls. That and only that will provide the second mic input.
However, I have at times used my MFi phone handsfree. I put it in my shirt pocket with the phone mic at the top. It work fine for infrequent use. No complaints from the caller.