I posted this in response to the github issue and I hope it helps you as well!
This is a feature of browsersync, which mix uses. bud does not use it. Someone could make an extension to support browser-sync but that’s not currently on the roadmap for this project.
But! It is pretty easy to set this up on your own with browser-sync-webpack-plugin:
Install the plugin and its dependencies
yarn add browser-sync browser-sync-webpack-plugin --dev
Add the plugin to bud
The bud.use function allows you to add webpack plugins in your bud config. just require the plugin, add your configuration and pass it as a parameter:
const bs = require('browser-sync-webpack-plugin')
bud.use(new bs({proxy: 'http://example.com'}))
I just tested this and it works well. Browsersync will run on port 3001 because bud’s default server is already running on port 3000. Both will run at the same time without issue so you can take advantage of bud’s development server while still doing cross-device testing (or whatever your use case is).