What do you think is the highest reason to forgive? For example, is the morally highest reason to forgive to preserve my own emotional health in self-care? Is it to help the other person to live a better life?
Those are very good reasons to forgive. I would say one of the highest reasons to forgive is this: to exercise goodness, particularly love, as an end in and of itself regardless of how others react to your offer of forgiving and whether or not you show immediate psychological improvement. In other words, to offer love regardless of the consequences seems to me to be a special reason to forgive.