I noticed that Zope 4 dropped the ReST shim and that a conditional import was added to CMFDefault but there's no note about how to integrate this.

The note in Zope 4 suggested that it should be possible to use docutils directly but that would ignore some of the parameters passed into the old ReST module. As a worked around I created a local ReST package using the old Zope code. This works well enough but I wonder if there is another approach.