My sunny side ups usually has pretty fried whites too, I guess… I make sure to bother the bigger white areas which tries to stay raw… I rarely bother with pouring fat on top but that surely makes it pretty “safe”, it gets properly fried, after all.
I know this thing about the avoidin/biotin since ages but as I mostly live on eggs including yolks so my biotin intake is quite high, it’s no problem for me to eat some raw egg whites per day and I don’t even do that, it’s usually just one or less (except when I eat multiple very soft-boiled eggs with runny, barely white whites. that’s good stuff). But I don’t forget about this avidin/biotin problem, it’s a valid danger for people (and animals) who eats raw white whites without a high enough biotin intake.