Yes, cost is a factor...no doubt about that. But I think that is offset by the higher esteem in which Pt-pd prints are held by most.
I think that because of the higher cost and perhaps the greater degree of experience/knowledge that pt-pd printers usually possess, that most know how to expose and process the camera negative so that it exhibits repeatable and foreknown density scale characteristics.
The one characteristic that hand coating silver would offer is that the print would exhibit more of the pt-pd characteristics so far as the emulsion residing within the paper rather than sitting on the baryta layer.
So far as the requirement of a long tonal scale requiring a high dmax, I don't follow your reasoning on this. The difference in the materials is such that the dmax (whether it is 1.65 or 2.10) is not related to the distribution over which the rest of the tonal scale is represented.