Make locale a document level setting
Many researchers whose are not native english speakers do some of their writing in their native language. For example, for me in a normal day there might be up to half a dozen transition between writing something in English and writing something in Finnish. Switching Zotero language trough the about:config screen gets tedious.
Because the language of a document determines what locale the bibliography should use, locale should be made a document level setting similarly to citation style.
Because the language of a document determines what locale the bibliography should use, locale should be made a document level setting similarly to citation style.
https://www.zotero.org/support/dev/citation_styles/style_editing_step-by-step
http://citationstyles.org/downloads/specification.html#the-root-element-cs-style
That should work in official Zotero as well.
Are there any potential downsides? Like, could there be people writing in en-GB English using en-US styles (single quotation marks and position of commas being the main differences)?
I do no think that it is technically possible to detect the document language automatically because, as far as I know, in Word language is not a document level setting.
For MLZ, I agree that it would make sense to add the bibliography language setting to the other document language preferences. It will be a month or two before I can get to it, but I'll put it on the list.