Idea for Bottom Lane Tower: Power Surge (Multi-Shot)

Power Surge is Bottom Lane's replacement for Fortification. Since multiple champions are in Bottom Lane, what if during the first 5-7 minutes of the game, Bottom Lane tower will deal 10% increased damage as additional true damage and shoot up to 3 bolts at one time, but the extra shots can only target enemy champions. This way it is harder to dive laners in Bottom Lane without making towers harder to kill and therefore increasing the duration of the game (which is at an OK point right now, going usually from 20-35 minutes). This would probably increase the duration of the game, but only against enemies who frequently target Bottom Lane.