Sorry, I hadn't had time to look at this until today. The good news is that it's been really simple after the introduction of the permission "Access in Control Panel" that was done after the initial attempt to fix this. All I have done to support this is to remove the following line from the liferay-portlet.xml file for the related portlets:
Then assign the permission "Access in Control Panel" for the portlets for the roles that you want to assign to the users that should have access to them.
You can do this in a Liferay 6.0 installation and it should work. We'll do this by default for 6.1 and assign the permission to the User role so that the default behavior is the same but it's easy to change through the roles admin.