I'm glad, too. This sort of scepticism is one of the pillars of science. Like, just because it seems solid (it does, for me) it doesn't mean that it's true.

A factor not mentioned by either the research nor the article is that [f v] sound considerably sharper than [ɸ β], so there are contrastive reasons to shift the fricatives from bilabial to labiodental if the effort necessary doesn't make them too convoluted to pronounce.