Right now we make our best guess at a useful default prompt, but don't support any customization.
The likely path forward is for us to put a nicer UI on prompt customizability and support generally useful prompt features like git status.
Another option would be to fall-back to PS1 for prompt rendering, but that would mean we'd need to support a full terminal grid in the prompt section of the input. I think we would probably only do this as a fallback, not the primary customization method.