Application Language

I'm not sure I follow: you first mention Metadata and then data.

In terms of Metadata, you'll be able to store anything you want in the Description field of Account members.

In terms of Data (i.e. annotation, footnotes, etc), as long as the database is not somehow misconfigured, it will be fine to store and display any such text through the interface. If you are going to build custom Connectors that import such data, you might have to pay a bit of attention in your code to handle them correctly using standard .Net practices.

Hi,

In Onestream the culture setting can help with displaying account of description of languages based on cultural setting, if you have cloud server you may first need to make sure the language packs like Chinese were correctly installed (should have been required by clients to Cloud provider).

Second thing is, if you are using (enhanced/advanced/customized) metadata builder to bulky load the metadata with description in different languages, always make sure the xml file will be saved/ encoded from local language to UTF-8, otherwise the loaded result will be with strange marks. 

Third thing is, for data loading the connector with Chinese is good; if the loading is via flat file, when convert xlsx from csv, the csv - UTF8 should also always be chosen to avoid losing characters (same case for Chinese & German).

Hope I cover as many useful cases as possible.