I wonder if A4 will specifically address the decisions made about trading lives.
Cap is very vocal about it, insisting that they not sacrifice Vision to destroy the mind stone. But all four stones that the heroes have anything to do with end up involving this moral dilemma.
Gamora eventually gives up the location of the Soul Stone to save Nebula (and StarLord couldn’t kill her earlier on his own to prevent that from happening either).
Dr. Strange eventually gives up the time stone to save Stark.
Loki gives up the space stone to save Thor.
On the surface, it certainly looks like sacrificing a life would’ve been the right call in every one of those situations. Of course without perfect knowledge of the future, none of that is certain (and Dr. Strange might know what he’s doing), but I wonder if this will be further explored, or if what we saw in Infinity War is about as deep as they’ll go on that.