Re-reading Tom's answer just shows there is confusion what the MappingSource is, even though it's right in the name.
OP mentioning one-node to rule it all, in this specific context, means one-node to rule all parameters of Bitmap. I.e Tiling, Offset, Blur, Crop, Filtering, etc..
It does NOT mean controlling anything other.
Triplanar, CC, and MappingRandomizer are their own separate nodes, they don't replace any parameter of BitmapNode. It's completely different category of Node. None of them are "controllers". MappingSource is maybe weird name chosen by Vray, other softwares usually called it "UV Coordinates" which illustrates it's just detached Bitmap control centre.
I mean it's ok for Corona Devs to disregard requests because they don't think they need it. But at least try to understand what is being requested.