Two Mackensens yearly trigger a much larger British program

How would Britain respond if Germany built two modified Mackensen-class battlecruisers with triple turrets every year from 1908?

Britain would adopt triple turrets, expand battlecruiser output, and perhaps build four battlecruisers plus six battleships annually to preserve superiority.

Britain must answer German battlecruisers while also maintaining a battleship lead over other powers, so the response cannot be a simple one-for-one match. British industry could sustain the resulting four-plus-six program if the political requirement existed.