Use the default parameter (Default) and the keypoints are rendered in a easy to read / scan unordered list with bullet points:
https://kagi.com/summarizer/?summary=takeaway&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DrgEV06ZfiZg
Use a specific language (french for me) and the results are displayed as one large paragraph, sometimes with line breaks, sometimes not :
https://kagi.com/summarizer/?target_language=FR&summary=takeaway&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DrgEV06ZfiZg
I expected the results to have the same formatting in any language, whether default, document language, or specific.