What are the common types of food waste that can be feed to insects but not directly to farmed animals?
Soldier fly larva will happily crunch away all the moldy or rotting household food waste you throw into a cold compost, but good luck getting a chicken to voluntarily eat much of it (and they'd probably get sick pretty often if they tried).
I assume industrial operations work essentially the same way, making use of the countless waste streams that livestock either won't consume or can't safely consume.
The bigger question for me is how they harvest at that scale. The hearsay I carry around in my head is that they just drown insect crops in chemical pesticide to harvest them, which I'm hoping is not the norm.
I've had a cold compost as a part of my backyard chicken coop for many years. All kitchen scraps, as well as all yard waste, ends up there. Moldy fruit, veggies, breads, literally everything including things like turkey carcass after Thanksgiving. I've never had a chicken get sick off it and the food scraps are quickly either consumed or dug into the pile, no rotting mess. Every spring I dig it all out for the garden. It works out great.
What about just heating up or cooling down the space they're in beyond their tolerances?
I'd flood the bioreactor with inert gas. Nitrogen ought to do it and we got plenty of it.
Edit: this company actually advertises that:
Pure nitrogen is used to control the growth rate before harvesting.
Your concern isn't so much about how they do it, it's about the regulations and how well they end up being enforced.
Admittedly, humans have a poor track record for getting that stuff right the first go-'round