I'm currently creating a new theme for my multivendor shop and using a child theme - it's a nice, clean and simple approach to modifying the appearance of the shop, and makes upgrading cs-cart more straightforward.
However, there doesn't seem to be the same approach available to modifying the backend. As our shop is multivendor, my vendors need to be able to login to an environment tailored to their needs.
In the past we made hard code changes to templates and style sheets - very messy to upgrade.
What approach should one make to do this correctly in the backend?