Are you talking about using fitting software to set the run parameters in a particular program or referring instead to changing things with the Smart 3D app?
My continuing experience with the ReSound Quattros on into iOS 16 on a new iPhone 14 Pro Max is that occasionally things get hung up for some reason. I’m not sure if it’s ReSound’s fault or Apple’s fault but quite a few times I think it’s the latter. To restore whatever’s hung when a problem occasionally does occur, I often find I have to power down and reboot my phone. Just force closing and relaunching the Smart 3D app often does not fix some problems. An example would be that the Smart 3D app shows one of the HA’s is not connected to my iPhone even though the aid is on and functioning well.
Maybe it’s just getting a far more powerful phone than my previous iPhone, the wife’s old iPhone XS Max, but the Smart 3D app runs like gangbusters on my iPhone 14 Pro Max. Loads immediately, shows battery states immediately, and switching to any screen in the program is very fast.
I have noticed in iOS 16 that when out walking and listening to podcasts if my phone is in a new holster case at my waist that BT streaming breaks up more than it ever has with previous iPhones and previous iOS versions. Could be the holster case or the MagSafe Apple phone case I got. But in the past, IIRC, I’ve walked with an earlier iPhone in my back pants pocket and had great BT streaming.
So I think Apple and ReSound might need to work a bit on performance/connectivity in iOS 16.
Perhaps the forum’s Oticon-oriented thread on issues with iOS 16 (and/or iOS 15) is an indicator that even Oticon and Apple are not entirely on the same page as well when it comes to connectivity and MFi firmware, etc.