Adultery involves exercising marital privileges with someone other than your spouse. It has nothing at all to do with "honoring the vows of her first marriage" nor "the abuser ... being victimized be her infidelity".

Amoris Laetitia adds nothing to any pastor's "flexibility to deal with such situations" since the internal forum belongs to the individual in question rather than the pastor. The pastor is external to the individual's internal forum.

Nor does it advocate, nor can the Church permit if its constant teaching is to be believed, dismantling of the consideration of marriage validity in favor of "nudge, nudge, wink, wink".