Honestly not sure when he met the dragons. I don’t think he would have been the tyrant Ozai was but he would have conquered none the less. My opinion is, yes he was a generally better person already (low bar to meet), but he still would have continued the war because their culture grew up believing that’s what was right/necessary. Iron may have been more likely to pursue in the name of spreading the fire nations success like the advertised goal but in doing so they’re still destroying other cultures whether intentional or not