Is it possible to enable the action to select the available views for a Foldertype? Or should i rename the document with the id "index_html". But renaming is for me the second option. Is it possible to tell Zope/Plone that the ID "index_html" is a normal, not a special, magic ID?
Rename the index_html document to something else, use the "Select a content item as default view" when you want to mimic the index_html behavior.