@david.hendon. Not sure where the sudden need to advise me on Optimize MFi arises several posts above, but I have been leaving Optimize MFi off basically since I started using an iPhone in Nov. 2020 and even complained to and got a response from ReSound Smart 3D App Support on the behavior of Optimize MFi back then: Resound Hearing Aids & iPhone 12 Pro - Connection issues/static, only one working w/static etc. Another aspect that I’d forgotten about (since I don’t use Optimize MFi) is that it inhibits the use of the Apple Watch thru the Smart 3D app with ReSound HA’s - perhaps my main reason for not using Optimize MFi.
Since I’m not privvy to how Apple and ReSound make things works, my guess as to what’s going on is that the basic connection and control of MFi HA’s is through the Apple OS, e.g., you have to pair your MFi HA’s first to your iPhone directly through iOS, then again establish a connection with the Smart 3D app. So the Smart 3D app is basically an app piggybacked on top of the underlying iOS BT LE connection. So it would seem that Optimize MFi is basically turning off add-on things that the Smart 3D app is doing (Find My Hearing Aids, Apple Watch Control (mitigated thru the 3D app) to let the main backbone iOS MFi connection have the fullest possible throughput between HA’s and iPhone (otherwise, at some level you’re stealing processor cycles to do other stuff, pay attention to polling results from listeners, etc.). I did feel that I got better, clearer streaming audio when using Optimize MFi (placebo effect?) at the expense of Smart 3D app responsiveness. The number one hit in response to an Optimize MFi Bing search is the following hearing aid business site where the commentary seems to also imply that things are being turned off or downgraded in functionality in the 3D app to optimize the MFi connection, which comes out of iOS, not the 3D app per se. ReSound Smart 3D App Update - Optimize MFi Connection - Davidson Hearing Aid Centres (davidsonhearingaids.com)
Edit_Update: The Davidson Hearing Aid Centres page ends with a quote that’s directly out of the ReSound Smart 3D v.1.2.2 release notes as quoted by JordanK on 7/11 and also 7/18, 2018: Resound just updated their Smart 3D app
Optimize MFi connection is defaulted ‘Off’ in the app. If a patient reports connection or streaming issues, they may choose to turn this feature on. If the patient does not report any connection issues and desires the full benefit of Find my hearing aid the Optimize MFi connection should remain off.
The prime effect of patient concern described is that running the Smart 3D app with full app HA connectivity and full app performance enabled (including Find My and Sound Enhancer features) may interfere with MFi HA BT connectivity or HA streaming - nothing about concern for patient benefit in optimizing switching iOS devices - although that too is a benefit of going to Optimize MFi on, as mentioned earlier in the release notes.