But margarine was such a healthy alternative to butter, all the advertising agencies told us so for decades!

I have no problem with them trying it, although I worry about weird prion based diseases cropping up that would make a living breathing creature non viable and die, when it wouldn’t be noticeable in something lab grown until far too late (i.e. after humans have consumed it).

Basically the fact that a creature is not dead might mean that its constituent proteins are likely suitable for consumption? Obviously not bulletproof, as mad cow exists, but lab grown meat might have a much wider homeostatic range, since it doesn’t have a brain how would you know it has prions that could negatively affect brain function? How could you even test for such a thing?