Cropping text is one of the most expensive operations in the old awesome bar, because we basically decide on a match base what to crop. Usually we never crop actions or tags, but we crop title or url. We try to make so that most critical parts of the url (like the origin) stay visible, and a part of the title should always be present. The old awesomebar crops with ellipsis, that additionally complicate things. Moreover there's no support in the platform for middle-crop that would be extremely useful for urls...

Hi Marco, Could I take up this issue?

I'm sorry but I don't think this is a simple or mentorable bug, there isn't even a proposal yet. You may want to have a look at https://codetribute.mozilla.org/ instead.