Current upgrade procedure for eZ Enterprise opens the door for using demo during upgrading, unlike Platform where clean is the only one referred to.

ref: https://doc.ez.no/display/DEVELOPER/Updating+eZ+Enterprise

This should be aligned, we should advice people to use clean so they don't end up merging in demo features being added in demo on newer versions which is irrelevant for them.

Possible highly relevant issue:

• Make sure clean can be used for install and upgrade (afaik might be some issue here since there are no templates provided for landing pages at all causing issue for installation and also causing issues if we advice people to switch to clean)