.He only used it when there were breaks in action
It's the exact opposite.
Like the post you yourself linked (which you seemingly did not read) said: "The implication here is that Double Strike/Thrash usage only happens when regeneration spikes (due to an unexpected burst of m/r attacks)."
Pre 2.0 it was optimal to use Double Strike/Thrash at times when the tank gets hit a lot by attacks that can be shielded or avoided by defense, which causes them to regenerate more force than usual.
Not when there are brakes in action, since at those times the tank would gain less force.