[VoiceRSS] Howto make use of different voices in a rule?

With the implemented VoiceRSS it is possible to select different voices under the language settings.
When trying to use this setting ( default voice for openHAB but not the default of VoiceRSS!) It is used only if the say command is used just with the text-string to be spoken. Whenever either the language or the AudioSink needs to be given ( the later would need language AND AudioSink) only the default voice of VoiceRSS for that language is used.
IMHO the overloads for the say command are the problem, since one can’t select an AudioSink without specifying the language.