Witch Hunter and Concentration question

Hi there, I find the Concentration mechanic interesting but from the current wording it seems weak for endgame content.

If you take Witchbane (Enemies have Maximum Concentration equal to 40% of their Maximum Life. Break enemy Concentration on Hit equal to 100% of Damage Dealt. Enemies regain 10% of Concentration every second if they haven't lost Concentration in the past 5 seconds.) in combination with No Mercy (Deal up to 30% more Damage to Enemies based on their missing Concentration.), how will they work with boss phases?

Best case scenario you deal up to 30% more damage for the first 40% of the boss's life and after that a steady 30% if you keep pumping damage at least every 5 seconds. That's already kind of quirky but since the Witch Hunter has Decimating Strike (initial hit takes between 5 and 30% of monsters life before the actual damage of the hit is inflicted), there's a way of getting started relatively quickly with Concentration.

But that 5 second counter is very bad if it still ticks during boss phases. Especially if boss phases don't also heal the boss (as your Decimating Strike can no longer help). Not only do you lose damage, but you also lose the defensive aspects of Concentration.

Does anyone have any insight on this?

Cheers!

TLDR: I really hope Concentration recovery timer stops during boss phases.

Would you be able to post what you can get about how Concentration works? I don't know either.

I would think it works exactly like the timer for Energy Shield, so if that recovers on boss phases, I would think Concentration also does.

Bump. Has anyone got a link to someone testing this ascendancy?