Hi, David. Even within the Smart 3D app, the first point listed for “Optimize MFi” is to improve the connection to optimize streaming stability - faciltating the switch between multiple iOS devices is listed as the second purpose. It’s hard to find an original ReSound description of “Optimize MFi” on the Resound Pro website but here’s quoted ReSound PR material from 2018 on the Hearing Tracker site on what “Optimize MFi” is all about. ReSound Smart 3D app "Optimize MFi" - #3 by JordanK
Since both streaming audio and hearing aid control are through BT, it’s just my own experience when Optimize Mfi is in effect, the phone/HA pairing for streaming is getting more focus and the BT streaming related to app control is less responsive than with Optimize MFi OFF. The fact that ReSound has made the default setting for Optimize Mfi as “Off” perhaps is ReSound’s vote itself as to whether without audio streaming problems is Optimize MFi best left ON or OFF. My perceived problem is in the Smart 3D app’s responsiveness. Perhaps the ON setting for Optimize MFi also chews more phone/HA battery??? To my mind, that fact that Find My Hearing Aids no longer works is also an indication that more attention is being devoted to maintaining the audio streaming BT connection and less attention to anything else.