Fast Refresh doesn't appear to work with older version (16.8.x) versions of React. I was able to reproduce this via this issue https://github.com/vercel/next.js/issues/14895
I updated all examples I found of React `16.8.x` to `^16.13.1` so that future installs will auto bump to the latest minor version. Previously the pinned version was causing the lock of version.
As discussed this adds an example to demonstrate how you can achieve proxying upstream requests that didn't match any pages/assets in Next.js which can be helpful in achieving incremental migration
