I recently wrote a tiny alternative to the mentioned webpack plugin https://github.com/nfour/TinyWebpackUserscriptPlugin

Using it in this project with some userscripts (see webpack.config.ts): https://github.com/nfour/userscripts

Tampermonkey seems like the best script manager for developer experience (as far as I could tell from trying the others) when configured as recommended (removing cache checks etc.), though it still requires 2 page refreshes to show changes.

If anyone knows of an improved workflow I'm all ears. I'd like to see something closer to webpack hot reloading, though I suspect we either need a new script manager, or a userscript framework that can be configured to hotswap code.

Perhaps browser managed content scripts will be viable? https://github.com/violentmonkey/violentmonkey/issues/604