Given that different people will find different things morally ambiguous, I'd rather DAI aim to have a variety of moral dilemmas that may or may not be seen as ambiguous rather than aim for moral ambiguity without that diversity. At least then they'd be more likely to hit more types of ambiguity.
The most common moral delimmas in Bioware games focus around The Greater Good. Generally they pose a question of 'is it better for a few to suffer to benefit more.' It may play with the degrees of harm or risk, but they tend to follow that pattern. Kill one in the name of protecting a hundred more.
That's too limited. Besides the fact that such security dilemmas were frequently subverted by never having a consequence be payed (see- Paragon risk-taking in the ME trilogy), that type of delimma is pretty unambiguous to someone who follows a greater good morality, someone who would always pick the many over the few. You could muddle the water by making the costs speculative and potential rather than immediate, but that's just changing the cost calculus rather than the moral delimma itself.
You can have different sorts of delimmas that test different sorts of morality. The Geth Heretic choice, for example, was always going to functionally commit genocide against Heretic Geth. The Collector Base decision pitted 'tainted' technology against potential gains in the hands of untrustworthy people. The Dwarven King crisis pitted two different aspirants for the Dwarven throne. The Old God Baby was about faith in a companion.
Not all of these were hard for everyone- but they provided more chances to be challenged in different ways.