Cash Shop Specials: 10/3 - 10/9

"Has an 80% chance to add 1 line of Bonus Potential to an item. If an item already has 1 line, has a 40% chance to add a second line of Bonus Potential."

The way it's worded probably makes it only unclear to me, but can the Gold Slot Carver add a second on reveal or does it first require one slot already be carved?

The "if" implies the latter.

To illustrate further, do advanced enhancement scrolls have the ability to add 10 stars with one scroll?