Well, there is a "Troubleshooting" category, a small percentage of the problems reported in this category are actually bugs. For it to be declared a "bug" it is necessary that the problem can be reproduced on a "clean" version and that only the technicians of UNA Team can do it. If it really is a bug, then a ticket is opened and a fix is quickly published. You can see them here. As you can see, there are few, these are minor issues and the fix is available for whoever wants to apply it right away. So when you say, "UNA is full of bugs" you are giving things a misnomer as they really are, I think, and I don't know how it could be done better.
Most of the little issues like the one you are having with notification -1 are difficult to reproduce, I have never encountered this on my installation, so try to give the specific conditions they occur under if you can, this would help a lot. But I appreciated your complaint in your post, it made me laugh :-)