I believe the reason some experience power related issues while others don't is outside temperature. The southwest US is not northern Europe. It gets consistently hot here for several months each summer. Consider the German motorcycle tourist who died from heat exposure (earlier this summer) while riding in Death Valley.
My iPhone 14 will charge with a USB cable, but will consistently stop charging because the battery gets too hot. The screen then sometimes dims, which makes the reading the screen almost impossible. It's simply not heathy for the phone even if I ignore the situation.
The app is very good. It's the closest phone app I've found to functionality in the Garmin XT. It's not a fair comparison in functionality since the Garmin is a full-feature standalone GPS. But again, MRA is remarkably good.
So for the time being I don't use it. I'm watching carefully what's happening with the HERE saga, and hoping there will be a solution at some point.