[Fuzzi]

Originally Posted by kovidgoyal

First you wanted fixed width, I said no program does that, which is true.

I still want fixed width.
Max-width is a compromise which would also be good and definitely an improvement. I'm open to that.
That programs do have fixed width (and a ton of max-width), see proof in my post before and in every Microsoft-product.

Originally Posted by kovidgoyal

So now you say you want max width, with word breaking.

Word-wrap is a necessity whenever you limit the width - no matter if fixed or max.
Cutting the words would be ugly and placing ellipsis also isn't acceptable imho.

Originally Posted by kovidgoyal

so trading vertical space for horizontal space does not make much sense to me

We're talking about 5px vertical space (red in my example) as a tradeoff for a clean, tidy menubar with less waste of width (~30% = 45px in the example and for more than half of the default items) and therefore more directly usable items!
Let it be 10px vertical space if you want more padding.

Originally Posted by kovidgoyal

feel free to propose it to the Qt (Qt is what calibre uses for its widgets) developers

Uhm, ok, never heard about that before. Is that the right one?
https://www.qt.io/
I will let you know their answer.

However, thanks for hearing me and giving answers.

@jbacelar
Thanks. But if some new code is needed anyway I'd rather ask the ones for the solid solution first (QT) which will be beneficial for everyone than asking an addon author for a custom workaround.