Only things bad I can find on the internet search is (1) "Raw" egg whites contain the protein Avidin, which binds vitamin B7 (Biotin), but is inactivated by heating to about 140 F for 4 minutes, (2) risk of salmonella infection. Heating up our mixes eliminates those two.
Sure would be a nice, easy, relatively inexpensive source of protein rather than just feeding our girls "empty" calories. Just seems like others a lot smarter than me would be promoting it if it was good.
I'll look up Ernie's posts, maybe that would shed some light on the topic.
Steve