I threw together a small PoB to show how much cooldown recovery rate is possible on a non-sabo https://pobb.in/6G3L7tMoOaxu. 0.33sec (3 warcries per second) seems to be the realistic lowest cooldown you can get. This translates to 1520% increased damage from the two weapons + the admonisher node on the tree, and 45% of life recovered per second.

Localidentity (developer of PoB) has confirmed that both the game and PoB add the crucible mods together to 200% more cdr rather than separate 100% more multipliers. The reason PoB shows 0.66s vs 0.63s on the in-game tooltip is that PoB rounds up to the nearest server tick (0.033 seconds).