First, if you allow the app to track the location, the battery will drain at an alarming rate. Second, the app does some of the same annoying things it does on my old phone - constantly separates controls from single sliders (which I want) to dual sliders, responds to commands slowly, if at all.
Maybe the difference is that I have a 2022 iPhone 14 Pro Max. I don’t have any of these problems.
I have the Smart 3D app set to “Always Track.” According to the iOS Settings, Battery applet, the Smart 3D app uses 1% of my battery power. I do almost always operate my phone in battery power-saving mode in which app background refresh is not allowed unless the app has focus and I am not moving around my house with my phone. I leave my phone in one place as I walk around my house and my yard (I have an Apple cellular watch just to avoid having to lug my phone around and to always be connected if I have a cardiac event - I have tachycardia problems).
I don’t find the sliders always separating into separate right and left channels or the Smart 3D app slow to respond.
Perhaps your problems are in choice of phone, not so much in choice of hearing aid? Although I have Omnia 962s. Perhaps there are some differences in performance from the Jabra Enhance Pro 10 although other purchasers of that model don’t seem to have as much problem, from what little I’ve read.