I've summarized the data in this letter:
https://www.bmj.com/content/366/bmj.l4968
In randomized trials, the fresher blood arm is associated with a higher incidence of nosocomial infection (immunomodulation, presumably). There has never been any data examining clinical outcomes that actually favors using very fresh blood. Mostly just "expert opinion" and "it seemed like a good idea." That's not good enough now, in my view.
Two key references (one only published in abstract form) are:
Alexander PE,
Barty R,
Fei