I actually released my extension around the same time that the Quarto extension came out. Quarto is great for documents running R code or needing some of Quarto's advanced document features. My extension has scroll sync and the preview updates live while you type. If you need code execution, you can use multiple Jupyter kernels per document and execute inline code. Also, code execution is non-blocking, so the preview still updates when you type, and code output appears live as it becomes available.