Rated 4 out of 5 stars

seems the html code was filtered by AMO. If I use round brackets instead of angle brackets, and bspan for the end of span tag, then I meant set a HTML template as

(span)xxx(bspan)(span) xxx(bspan)

This review is for a previous version of the add-on (0.4.0). 

Thank you for the valuable information.
Fix bug at version 0.4.1.
I wish it become operation for which you hope.