You may use this as a starting off point for your own CL.
Don't go above Webpack 4.16.2 - as of this writing, there is a bug with output libraries. Unclear what version introduced it, but 4.16.2 for sure works.
To use hot code reloading, set window.ComponentLibraries[CL].MythosApp.HotReload
to a function that accepts a React component, and renders it in the mounting element.
const CL = '@my/cl-name'
const render = (MyApp) => {
ReactDOM.hydrate(<MyApp {...window.__PROPS__} />, document.getElementById('app'))
}
window.ComponentLibraries[CL].MyApp.HotReload = render