It would be useful to have a tool to easily insert
attribute epub:type. There are a lot of them and if you want to use them, you have to be motivated.
As I see it:
It is an entry in the menu "Insert" (conditianal to ePub3) that opens a dialog, similar to the editor of semantics of the HTML elements, and once the epub:type is selected, it is added to the tag in which the cursor is found.
Officially, each epub:type is limited to a certain tag, but in a first implementation, I think you can get past that. Once the base is done you could refine the feature to be compliant with the standard.
It would be very practical.
Thanks