I haven't got around to reading what the "real" Yajnavalkya said. In this book I mention, which Mark Jeftovich referred me to in his "Bombthrower" blog (he is a recently minted maxi btw), they don't actually mention this character but they talk a lot about the text Vishnu Purana. I have been meaning to read that one, The Book of Enoch was awesome, and I'm kinda struggling with Corpus Hermeticum but I am betting I like Yajnavalkya a lot.