Same. mitmproxy (and its built-in mitmdump lib), along w/ the (criminally obscure / amazing) lnav (https://lnav.org), have served me very well in the past for this kind of thing.
I have seen Inav earlier but never used it. Does it also provide response modification capabilities?
No, at least not out of the box, bc that's outside its intended realm; lnav (short for log navigator) is like a mini-ETL CLI powertool w/ embedded SQLite. You can pipe (semi/)structured data in, then query and optionally transform and/or export it out. Its API makes it convenient for chaining w/ tools like mitmproxy, so you could do almost anything with it in a custom script pipeline.