Wow I hadn't even thought about using the top bar for these sort of things. Good idea! Too bad it doesn't work on Tampermonkey :(
I just did a quick test with chrome and I couldnt get it to work. Not sure how to fix it but I will take a look at it again later.
The thing is, they are using jQuery-ui's selectmenu widget. I don't know why it's working on Firefox, but you should refresh the widget after adding the options:
This should do, at least for the visual glitch (there may be other unrelated problems).