First, it still interrupts the battle, no matter what. That interrupts the last card, if played in battle by an opponent, and all ongoing effects on cards played in battle, so the ItB still does something.
The artifact cannot be triggered during SI, no. However, you don't actually need initiative to activate it (because it doesn't say so), so you can activate it immediately upon being blocked or at any point during the block when other abilities are not resolving.
The Wiki entry is indeed incorrect on the SA; this card only searches for cards that specifically have "ignores" in the SA, not an ignore ability.