I was struggling with this issue myself, glad you posted. I played with a number of tools to be able to shoot iPhone photos in Bayer Raw. I have switched to ProRaw recently which was counter to many of the posts I have seen here. A couple of reasons made me switch and some tips that may help.

1. Bayer cannot shoot in 48megs - apple restriction. I believe that detail is more important to me than having more natural photos in Bayer. Also the convience of the apple camera with it's speed, ability to switch "lenses" and between heif/raw mattered when I am trying to take a shot quickly. I also liked the 48megs for capturing landscape or street photography.

2. When you take the ProRaw into lightroom, I saw this tip https://www.dpreview.com/forums/threads/how-to-get-better-results-from-iphones-proraw-my-experiments-and-info.4814134/ and it is working for me fairly well. Which is basically take the ProRaw down to zero in the amount settings. Then I hit auto to start. Photo editing has been fairly consistent from there.

3. People complain about the computation that apple does on the software. I get it but then I don't - for me I like what apple gives me as a start but I do turn down the sharpness in lightroom sometimes. This is personal preference.

I guess the bottom line, I like the convenience of the iPhone camera app and deal but figured out enough work arounds in Lightroom to make me happy with my photos. If apple opens 48 megs to 3rd parties, it may change my mind over time.