I enjoy a good Solas analysis as much as the next person, and I like exploring all the ways in which the trauma he experiences may have influenced the many terrible decisions he makes.
At the same time, I hope we remember that it's okay to not be able to explain everything away. Solas has done terrible things, and we can't tie every single one back to an explanation that justifies it in a way that keeps him "pure".
Let him be murky. Let him have felt full-throatedly that the acts he committed in Mythal's name were necessary to make his creation of a physical body and subsequent service worth it. Let him fail to fully appreciate what he did to the dwarves/titans. It's only by viewing his flaws and harms in their entirety that the most exciting parts of his arc (at least to me) can be contemplated.
How far is too far? At one point do the wrongs you've scarred the world with become impossible to assuage through better intentions at other points in your journey? Can you learn through your friends and loved ones lessons you refused to be taught earlier, that caused you to hurt the one who tried to teach it to you? Can you make him see that it's not just the spirits and the elves that deserve restoration, but the dwarves? (We didn't get the opportunity to really dig into this particular avenue in Veilguard, but I think the fanfiction potential is ripe). What does he become when every possible method to reach him fails? How does Pride doom himself and leave no other choice but to put him down like the dog Elgar'nan declared him to be?
Idk. I have concerns that occasionally there's a binary standard applied where he's either wholly Solas or wholly Fen'harel with the implication being that he's either all good and every action actually stemmed from that place or singularly bad. When in fact, the coolest place for me to dwell in is the one where we have the moments where Solas raises his voice or plays a cruel trick because he's so exasperated, or where Fen'harel may have stopped to pet a halla on his journeys if for no reason other than to feel soft fur against his fingers.
He is at his most interesting when he is at his most complex, and when I say complex all I actually mean by that is when we let him be real, permit him to breathe within his own story and not just the ones we rewrite to make him more palatable, we do him more justice. Give him room not just to grow and evolve, but to dig in his heels and become the monster he never wanted to become. At the very least, he has near-absolute power in a world that by comparison feels very powerless. He's going to be just a little bit corrupted by the weight of wielding that power. The story will only get richer and more compelling if we let it exist in its entirety.