My personal thought on the bugs in the feed is this (but someone correct me if I'm wrong, please!)
-I think the bugs are fine for the birds to eat.
-If the bugs have eaten too much of the feed, it will change the nutritional profile. However, if they can catch the bugs and eat them there may be better nutrition in the bugs (!)
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Oftentimes buggy feed comes with moldy, wet feed. The kind of mold that grows there often has aflatoxin which can be DEADLY. My guess is that folks put "moldy" and "bugs" into the same category and err on the safe side by advising people to get rid of the feed "just in case".
Now, for me, I want them to be dead before sticking it into the fermenting container and I definitely want to stop the infestation in general. My feed is dry (which doesn't really mean that aflatoxin isn't present anyway) but I'm going to assume it is not full of bad mold...
ETA: This is another reason I focus on LACTO-FERMENTATION (which proliferates LABs that produce lactic acid) rather than alcohol fermentation (which proliferates yeasts which produce alcohol, then acetic acid. LACTO-FERMENTATION produces an environment in which many yeasts and molds are kept in check if it is kept in balance with the LABs in dominance.