Overview
KSVK’s Skill 2 makes her target the nearest debuffed enemy and deals an additional 0.3x Damage to the target and enemies behind the target. This multiplier is abysmal and against ever-growing enemy health pools just ends up tickling the frontline, while offering nothing valuable towards actually killing the dangerous enemies in the backline. Making this even worse, is that it is not linksplash and cannot Crit, which for a RF's normal attacks is absolutely terrible.
Her Mod III equipment is a high AP Sniper Ammo, making it largely useless as her Skill 2 ignores Armor. Though it is useful for her regular attacks it is not worth it to Mod III her for this.
For the niches of frontline or AoE Damage, there are far better options.
Some examples for AoE there are: Hanyang Mod, M4A1 Mod, 416 Mod, Kord.
Some examples for Frontline targeting are: General Liu, SCAR-L with SCAR-H, M4A1 Mod, most ARs.