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I don't know about any refutation but the only time you don't get to use the setup is when White wants an endgame.
I believe you should play Nd7 before e5 to avoid exchanging queens.
Nope, I believe that runs into f4 and the exchange of queens is not to be feared at all, not a way for white to play for advantage at all!
GM Simon Williams reviews this game on his deeee veeeee deeee:
1.e4 d6 2.d4 Nf6 3.Nc3 Nbd7 4.f4 e5 5.Nf3 exd4 6.Qxd4 c6 7.Be3 d5 8.e5 Ng4 (Karjakin,S - Nepomniachtchi,I)
Black Lion DVD
The Black Lion, 2nd Edition by Jerry van Rekom & Leo Jansen (2009)https://web.archive.org/web/20140627122350/http://www.chesscafe.com/text/hansen123.pdfA Cunning Chess Opening for Black by Sergey Kasparov (2015)http://www.jeremysilman.com/shop/pc/Cunning-Chess-Opening-for-Black-A-76p3899.htmhttps://www.newinchess.com/media/wysiwyg/product_pdf/9008.pdf
actually that is avoided with Nd7