I have noticed that it is possible to specify multiple languages for one piece (e.g. when the piece is available in different translations) with the magic
Yes! I recently implemented Template:MultiVoicing precisely for the purpose of handling such situations. For the example you cite, the code would be:
{{MultiVoicing|v=3,4|n=2|1st=TTB|2nd=SATB}}
which would produce:
Number of voices: 3, 4vv. Voicings:TTB and SATB
For more comprehensive examples see the documentation included on the template page. Other examples of its usage may be found on the following ChoralWiki pages: