If using a 0.5 micron carbonation 'stone' that's actually held low in the keg/beer by a length of rigid John Guest 3/8 tubing, yes, it can speed up carbonation. Otherwise, simply forcing CO2 down the liquid-out dip tube won't make much difference. Surface area being one of the factors influencing the rate of carbonation. Even better, exploit the billions of active yeast cells suspended in the green beer by naturally carbonating in the keg, ideally with a spunding valve.