Meridel suggested to involve you for a UX perspective.
The way I see it, we have 3 alternative approaches to solve this specific truncation:
- Solve it at UX level. For example: change the app menu to actually fit the longest translation, accounting for keyboard shortcuts. Or allow the text to wrap at least on two lines.
- Solve it at "content" level, allowing translations to use a different label, i.e. "Extensions and themes". This could solve the specific case, not truncations in general, and even not necessarily for all languages.
- Ask translations to shorten their text. That's less than ideal, because it kind of treats other languages as a second-class citizen, and shortened versions might not be as easy to read for users.
For 2, copying from a conversation with Meridel to keep everything in one place.
In English, we felt that we needed to retain the word add-ons as a bridge to current nomenclature elsewhere in product — and that existing users are used to the term add-ons and would be confused if we removed it.
I personally feel that this applies less strongly to other languages: English users are familiar with add-ons because that's what shows up in URLs like addons.mozilla.org or about:addons. International users are somehow exposed to both the term add-on and its localized version (e.g. componenti aggiuntivi in Italian). But if, for example, you select Tools -> Add-ons in release, this brings you to a page where add-on appears only a couple of time (search field, support link), and it's less prominent than the titles in the sidebar (Extensions, Themes). So, are they really that familiar with the localized equivalent of add-on? Unfortunately, that's a feeling without data to back it up.
Even if, I would also not be advocating for "all locales should use Extensions and themes", more like creating space for a different approach if there are truncation issues, like it happens for French and Italian. This still leads to potential confusion, when comparing English and localized product.