Adding FastRefresh to ArcGIS Experience Builder Developer Edition.
FastRefresh is now part of create-react-app
https://github.com/facebook/create-react-app
(https://reactnative.dev/docs/fast-refresh)
ArcGIS Experience Builder (DE) is not running on webpack-dev-server
But there is React Refresh Webpack Plugin
https://github.com/pmmmwh/react-refresh-webpack-plugin
supporting ts-loader
And can be use also as webpack-hot-middleware
Just need to check if it's also working on Koa😉
https://koajs.com/