From a gameplay perspective it would be nice to have a second charge of Celestial Brew, as it does feel bad wasting cooldown reduction. However, you would likely fall into the same rotation of using celestial brew on cooldown to not waste cooldown reduction, and saving the second charge for an emergency. So the only difference would be having a charge for emergencies, but likely having Celestial Brew shield for less, or have a talent take the place of something else to grant a second charge.
I wouldn’t mind perhaps dropping the increased Celestial Brew absorption talent when purifying stagger to instead grant a second charge and baseline increase the shield by say 25%-50%? Perhaps make it a choice between the second charge talent or the stacking increased absorption from purifying stagger damage?
Our just use it when it’s of cdunless you need it for something upcoming while all those other mitigation abilities are down. It’s not the primary mitigation tool, purify is.
Celestial brew would feel infinitely better if it had 2 charges and half the effectiveness. I agree 2 charges at the current strength would be too good, but the wasted cdr from keg smash and the upcoming DF talents like A&S just feels bad.
Brewmasters function differently to those tanks you mentioned. Actually removing damage with Purify is way more interesting then spamming Ironfur. Brewmaster functions pretty close to how it did in WoD, except the real active ability we had back then was Elusive Brew, which was put into mastery instead.
Brewmasters are generally the best raid tanks due to the way stagger works (except for outliers like bdk at the moment), so it’s very unlikely they will be given additional mitigation or cool downs without a full rework.
This sort of mentality is like playing a Blood Dk and asking for a different mitigation system because they don’t like Death Strike for healing. It’s just the way the tanks work. Your best bet would be playing one of the classes you mentioned if you prefer the more traditional mitigation methods.