Seems like kind of weird timing for this article - FIS has banned fluoros, and their grip over the nordic ski racing world is pretty much absolute. by next season, any waxes with fluoros will not be viable consumer products.

They call out the american birkie for not having banned fluoros yet - that's because the FIS ban hasn't gone into effect yet. American Birkie is a FIS worldloppet race and subject to FIS rules.