Runners belt meets thigh rig, and they have a a child. (See SpiBelt and Nathan Performance VaporKrar, for examples of high-end runners belts.) To be clear, I am not minimizing the efforts of Phlster, or Phlster’s craftsmanship, but saying that the concept is valid.
I have been experimenting with carrying some very interesting things, using SpiBelt and Nathan Performance products, though the cover garment has usually been an oversized moisture-wicking shirt or hoody, but pulling one’s trousers over something like this makes perfect sense, too.