Interesting and nice to see a comparison chart of the major foods too.
I think that it is still important to note that any feeder animal should be well maintained and well fed before being offered as food. And some feeder animals we mention to avoid are partly because they may have been trated by copper based medications. Better safe than sorry.
It makes sense that FW inverts would be a better choice than FW fish as feeders, just the drawback of a FW shrimp dying after a period of time in FW if not eaten immediately.
I wonder how crayfish compare nutritionally to ghost shrimp though?