Following up on ayang90's post, Meitner informed me that this firmware update mainly addresses "how the MConnect app interacts with latest updates to Tidal, Qobuz, Spotify."
More from Meitner:
"You can use either the MConnect Control app or the MConnect ControlHD app (meant for tablets) to update your MA3i streamer firmware. It should be automatic and is applied OTA (via the network) when using MConnect Control app.
1. Select “Play To” and choose the MA3i
2. Once MA3i is selected select the “Player” button to go back to the main screen
3. Select the “cog wheel” (settings) on the top left corner of the MConnect app and select “Device Setup” from the drop down list
4. Select MA3i
5. Once this is done the app will automatically go out to our servers and look for any firmware updates.
6. Latest firmware (look down the list to “F/W”) after you update should be “….v4.4.58”