Developer reply by Realraven (Axel Grude)
Rated 5 out of 5 stars
just received an e-mail tutorial, detailing all the required steps to achieve my goal. Support is excellent in my case.
This review is for a previous version of the add-on (5.1).It's already there, and it is called "custom templates". With these, you can design your own templates exactly the way you described - please check the "Advanced" tab to try them out.
To create your own collections, you must have a Mozilla Add-ons account.