While some observers understandably argue that the the residual grey areas that I discuss force us to still be extremely
prudent, even at the present time one could legitimately describe as robust [62] the observational evidence
indicating that some -rays with energies up to 20 TeV are absorbed by the IR diffuse extragalactic background.
And some authors (see, e.g., Ref. [511]) actually see in the presently-available data an even sharper level of
agreement with the classical-spacetime picture, which would translate in having already achieved Planck-scale
sensitivity.