Development with git branches/ gitflow and new modules
I always have a somewhat up-to-date DB dump from live/master available. When switching between feature branches I can drush sql-drop the DB, drush sql-cli &lt; live.sql and drush cim the branch config. If needed. When switching back into the develop or master branch I do the same steps again.

This means you routinely have to commit your feature's configs into its branch. Or to write really cool install.yml in a custom module and enable that after you switched back into the feature branch.

I guess we will have something automating this in half a year. But for now, it's perfectly fine. At least for me.