Touch Bar icons & other problems

Hi, I’m experimenting a bit with the new touch bar support of electron.
I’m not able to use the icon option to display my icon, I get no errors, it simply displays an empty button.
Another thing I’m trying to insert a popover into another popover, but when I click into the second, it flashes for a millisecond and then it goes back to the initial touch bar element, any clue?

Last but not least, is there a way to use more than 7 elements in the touch bar? Having a “scrolling function”? As it works on safari’s display of bookmarks?

Thank you, Marco.