Upthread, I had, when I pointed out that Spock was capable of ruthless moral calculus. Most famously, and hemore explicitly for you, he chose to suffer an agonizing death from radiation poisoning to spare the Enterprise destruction from the Genesis Effect. If he is willing to suffer so much himself, I would think him willing to risk suffering on Romulus if it meant many people might be saved. Certainly he has the moral credibility to do so!
You are the person who is bringing in STO, which describes a very different timeline from Picard. One might as well bring in Peter David's MU novella, in which Romulus was depopulated by a thalaron bomb, to say that bomb caused the supernova. Hey, it is a licensed work, right? No matter that it describes a different timeline, one with very different events.
We do not see Data alive in the body of B4, in Picard, while in STO Mars is not burning after it was destroyed by synths in 2385. STO, critically, describes a supernova that occurred with very little warning and had mysterious superluminal effects; Picard describes a supernova that occurred with years warning and had entirely predictable effects. It is not clear to me what STO actually has to say about the events of Picard.