How to create language (billto-site language) dependent BIP invoice template?

Summary:

We try to find a way (Oracle supported or best practice) on how to use multi language templates depending on our customers bill-to-site language setup.

Oracle Fusion / BIP

Content (please ensure you mask any confidential information):

At this moment we use an approach which uses ONE Invoice template for the printing customer invoices. This rtf template contains specific conditions for different languages within the template. The language itself comes from the datamodel. But with increasing languages (and next to other conditional sections in the template) the whole template building and maintaining becomes quickly not very practical and risky as well also.