Lemmy needs an asksciencefiction for this.

I think they would be able to sustain themselves on it, but would constantly complain about how it is soooo different, even though it’s chemically identical. But really they’d just be missing the thrill of the hunt and the whole romance side of the lifestyle they’ve been living for thousands of years.

I think it would be interesting if a story had them using the lab blood like protein bars, something to hold them over but not something desirable.