To be allowed this to be done we have to redesign the menu and how it is formed...
Brrr... no other method to derive how wide the list may be....
I didnt found a reliable way menus to be resized dynamically together with containing elsments
Only thing that can be done is the menu width to be extended a bit initially.
The problem with the menu is that the width of the text depends on the translation.
Many translators will not pay attention where the text is displayed, and therefore two words in English may be translated as a sentence in another language.
This also applies to button translations.
In my skin, I use the applet onLayoutFinish and eLabel.calculateTextSize to calculate the text width and scale the menu size.
You have additional elements that make this much more complicated.