When you perform a Target Lock action, you may disable this card to acquire a 2nd target lock on a different enemy ship within range 1-3 of your ship. While you have this upgrade on your ship, you may have up to 2 different enemy ships target locked at the same time.
Typically when a card is disabled, the card text has no effect. Does the wording of "While you have this upgrade on your ship...." mean that the Multi-Targeting Phaser Banks card works to maintain up to 2 target locks even while disabled?