It is currently NOT possible to shoot photos in 48MP with the industry Bayer RAW format (the classic RAW format).
Our app Reeflex Pro Camera, when selecting RAW format, produces DNG files in the standard Bayer RAW format (CFA, Color Filter Array).
Since the iPhone 14 Pro/ProMax have a quad-bayer sensor, it can only produce 12MP RAW files (4 pixels are grouped in a single color in the Bayer pattern).
Note: Apple ProRAW format should not be confused with the industry Bayer RAW format, as they are two completely different formats. Apple ProRAW allows 48MP, while RAW does not.