Rated 5 out of 5 stars

Just rename the add-on from .xpi in .zip, open it and change in the install.rdf file "maxVersion" (I wrote 60) and when saving rename the .zip in .xpi. Then install the file in TB from the add-on page, and look: local folder is hidden! I just don't know how long it will work... I need some time to check it. Delete the add-on if you need the local folder again.

This review is for a previous version of the add-on (1.04).