Thank you! Very interesting research all around. I think these old German and Japanese languages may have been hard to understand for outsiders, but were used

Thank you! Very interesting research all around. I think these old German and Japanese languages may have been hard to understand for outsiders, but were used with high sophistication (you have to invest energy to access this information) among insiders. For instance the Japanese pillow words / Makurakotoba or German words for hard to translate concepts like "Weltschmerz", "Kummerspeck" and "Torschlusspanik". All short, useful words for communicating complex rich concepts, provided the agent knows the meaning of these words.