Answered: How can i display user name inside On Site Notifications popup?

This is now easier to do with the latest versions of the plugin. Although this would defy the purpose of hiding Up/Down votes of publications to regular users, as this could create toxic behaviors like: "Oh you down voted my post?! Then I'll go on a rant and downvote all of your stuff" ... 

That's why only Admins and Mods can see who casted votes when you hover over the Vote Counter.

This idea also popped in my head while I was developing the latest versions of it, because of the structure for Message notifications:

 Username  +  sent you a private message:  +  The message...  

(Which you can study it to recreate that for the upvotes btw. Line 189 and line 397.)

but then I didn't go forward with it because of that same reason.