Has anyone demonstrated yet that the hindlimb feathers were capable of
transmitting bending loads to the hindlimb skeleton?
Of course not. The basic issue of in which direction the hindlimb feathers
stuck out isn't resolved, and probably can't be from the flattened fossils.
Chatterjee & Templin's reconstruction is clearly logical and possible, but
that's all that can be said, AFAIK.