Hi, in category item listings the button for frontend depends on the category title visibility: if category title is hidden, then the "add new item" button won't appear.
This means that is impossible to configure K2 for frontend insert of new items while having the category title hidden.

I found a workaround by leaving the title visible by configuration, and hiding it via CSS, but this of course wouldn't work in case one needs to different configurations in different categories, you should consider a fix for next releases