I’m not 100% sure if it’s something you’re looking for but I use hashes in filenames too and I manage to update/insert the references with the Html-webpage-plugin. I use this with a template html file where the references to js and css got injected on build.
github.com/jantimon/html-webpack-plugin/blob/mast…
This is my repo with a sample project where I develop and maintain my configuration. The Webpack 4 branch is still WIP though
github.com/HerrVoennchen/sample-project
May it’ll help you with your configuration