I can say with certainty that low ready with your full recoil management arm triangle and grip fully established is going to be the most efficient way of presenting quickly and accurately to target.
If you want to take it one step further, START your process by aligning the dot on the first pin in full firing grip, stance and arm triangle... then slowly lower the arm triangle to the bench and wait for the signal. Only LIGHTLY rest the muzzle on the bench, you want the muscles already engaged before the starting signal.
Practice this in dry fire.
(How do I know what I know: Steel Challenge rimfire utilizes a similar start position for pistols, it's also a common movement and position to start long guns in IDPA, also in USPSA top shooters try and retain their triangle whenever possible and try avoiding breaking the triangle when they can).