@iternabe and @rogerch thank you both for the suggestions. I really just wanted to complain about the iPhone. π
And I don't want to add complexity to my recording activity. Not for now. I used to use the Zoom H1, but getting it out, plugging it in, getting it set up, then transferring the recordings to the laptop, doing any normalizing etc in Audacity, saving them as mp3s... It was just too many steps for me. (Maybe after I retire... π
Re clipping, I don't have clipping with my iPhone. The sound quality of iPhone recordings has changed over the years, and is definitely better. But it's also clearly not as good as what you would get with some kind of external mic etc. So maybe it's not flattening per se, but maybe it's just not picking up the full range... For what it's worth, the recording does sound better through a bluetooth speaker, and even better through airpods.
Anyway, I don't want to add equipment or processing, I just want the iphone mic to get better. π