Allow dropdowns with the menu part wider than the button part

[curiosity]

Right now it almost works, but the menu items are cut off, graphically and interaction-wise. From what I see, the menu part is an entirely separate element internally, so I don't see why it has to be limited to the button's width.

The application is making a "button with dropdown menu" kind of GUI you can find everywhere. The button does one thing, the dropdown contains more options for it. Here's a screenshot of one such button from another program in case it's not clear what I mean: