I do not think this even comes close to working. I have the Apple adapter for feeding an iPhone (using Apogee Metarecorder to do the recording) with a signal out of a Sonosax SX M2D2, and it is very good for this. But the DPA MMA-A is another animal, and most of the standard micro-USB to Lightning cables simply don't work. Using the DPA micro-usb to lightning cable (or the micro-usb to USB-A cable that also comes with the MMA-A for PC devices) through the camera adapter won't even pass an audio signal from the MMA-A to the DPA app, as far as I can tell. A power source hooked to the Apple adapter will charge the phone, but I can't record at all with it and the MMA-A.
I have tried the following at home (not live in the field) and it seems to work very well. Earlier this year a crowd funded project for the Futurizta Pixy Go delivered to me a wireless charging phone power pack, I got the smaller 5000 mAh version which weighs in at just over 4 oz. The tech guys at Apogee wrote me that they saw no reason why a wireless charger for the cell iPhone should in any way interfere with the operation of the Metarecorder app. I have just run the recorder for 14 hours with the Pixy Go active, it ran down the power pack all the way and left about 40% charge level on my phone (I usually can get around 10-11 hours recording), so the projected length I am good for with this is about 17 hours; of course, I intend to get a spare Pixy Go, which will be overkill until I upgrade my iPhone to a newer version with more internal memory to record to!
I have examined the files recorded in iZotope RX9 and see no signs of any hum induced by wireless induction from the Pixy Go. Just the expected room background noise that DPA 4060s pick up in other tests. I am not yet sure how stable this will be live, but when I need the extra milage I'll be checking it out.
Jeff