Clever Strategic Stance vs Demon Challenger

I'm having trouble deciding which potential to unlock for my bouncer's Nox Dinas...

Clever Strategic Stance - I am using Elemental Stance, but where exactly does the bonus apply? The description for Clever Strategic Stance states "Attack potency to Element Weakness while in Elemental Stance increases by 9%" , but does that only apply when matching elements, or does it boost non-elemental weakness % as well (considering that the skill itself does boost unmatched elements)?

Demon Challenger - Description is as follows... "Increases damage to weak point by 10% and critical rate by 50%" ... Is this as good as it sounds, or does it require the player be using Break Stance?

The descriptions and translations aren't always exact, so I figured I'd ask here before making my choice.

@BaNeOfNyC

Clever Strategic Stance: Applies only when matching Element.

Demon Challenger: It does not require Break Stance, rather it acts like Braver's Precision Stance, ie. with non-Techs, you must hit a physical weak point for it to apply.

@AndrlCh

I knew Demon Challenger seemed too good to be true...The description makes it sound as if you get a critical rate % bonus at all times. Thank you for the clarification. 😎