Hi!
Not possible in the current plugin state. I’m looking for a solution if there is an easy way to achieve this by modifications. Actually returning taxonomies as search results is maybe an extra 100 lines of code or less. The problem is to fabricate the url, where these results would lead the user. Apparently the url structure is something like yoursite.com/index.php?taxonomy_name=the-taxonomy-name but I can’t confirm this works 100%.
Let me check if I can make a modification to return custom taxonomies on my test server 🙂