If you’re in a web app, you just need a markdown renderer component right? I’m using react-markdown NPM package for mine. It has the ability customize rendering of inline code blocks (which is what you’re talking about in markdown), and I happen to be doing exactly what you said in my app. Fixed font for those.
If I were doing my own app and hitting the API, this wouldn’t really be an issue. I’m just using the regular ChatGPT chat interface. Though I wonder, for my personal use… Would it be pretty cheap to just hit the API and write an app myself? I have hit the API before but it seems like a bit of work to get to a chat interface as sophisticated as the one ChatGPT has.