Multiple dictionaries for spell checking

Sometimes it’s annoying to specify the language for every paragraphs of the document.
Think about a really big one with thousands of words in different languages.

In this cases, we would like to select al least two (possibly more) dictionaries as a source languages for entire document instead of selecting the language for every paragraph or, in worst cases, for every word.
Isn’t it ?

This sounds like a perfect request for a feature, or at least, for an extension.

I’m not sure, is it better to file a bug or to write on “Crazy Ideas” wiki page ?

I would certainly second the case for adding more source languages. I typically have documents with 3 languages, sometimes four and I find it painful not to have automatic recognition and a correct (adaptative) spellchecker behavior for my work.