I worked on some further improvements of the Plone addon tdf.templateuploadcenter. A site administrator is able to edit the allowed image and template file extensions. Thus I wrote a new validator for this file extensions. I created a field to inform contributors about the currently allowed file extensions (with dynamic content).
The add-on provides not only projects with releases but also small projects where the template files are uploaded to the small project content type directly.
Today I made a new release of this Plone add-on, which drives the current LibreOffice templates website. The Plone add-on and its release are published as Free Software under the GPL-2 (General Public License version 2): https://pypi.org/project/tdf.templateuploadcenter/