Kitoko's current - "unscalable value" - question

Hi guys. If I press ALT the context menu prompts "UNSCALABLE VALUE" right after the most important modifier of Kitoko's current ("lightning damage from hits contributes to electrocution buildup"). What does that exactly mean?

Why am I asking? The thing is that I'd like to enchance Ailments (electrocution is included in that group) proc using talents tree.

Thank you!

+

probably shouldn't be replying since im not 100% sure, but I THINK it means you can't scale the electrocution build up from lightning damage hits with increased ailment buildup nodes