That said, such a thing should be easily doable in a plugin now and sellable on the UE4 marketplace or direct. There are a number of pathways now that you could take. It could be you load the libpd dll and runtime, then on the pd generated output, feed it into a USynthComponent if you want the pd patch to be a single 3d source or feed it out of a submix effect if you want to do surround sound. Same is true of a juce host.