PH diphthongs

I wonder what PIE sources there are for these. As far as I know, Osthoff's law applied to Greek too.

Fair point. I suppose we can discount the hapax Ζηύς (Zēús) < *dyḗws as leveled from Ζήν (Zḗn)? I doesn't apply to diphthongs due to vowel hiatus like *néh₂us > *nā́us > νηῦς (nēûs), though.

Also, γραῦς (graûs) and maybe Θρᾷξ (Thrâix)

Sihler does not think there are long diphthongs and particularly explains away νηῦς. So should we remove them?