2019-01-25 : Addendum abilities of instant spells apply while the spell is resolving, not immediately after casting it. If the spell is countered, you don’t get the addendum bonus. For example, if you cast Sphinx’s Insight during your main phase, you gain 2 life during its resolution, after you draw two cards.

2019-01-25 : Code of Constraint can target a creature that’s already tapped. If you cast it during your main phase, that creature won’t untap during its controller’s next untap step.

2019-01-25 : If a spell with an addendum ability is copied, the copy won’t give you the addendum bonus. This is because the copy wasn’t cast at all.

2019-01-25 : If the target creature is an illegal target by the time Code of Constraint tries to resolve, the spell doesn’t resolve. You don’t draw a card.