In situ stress monitoring has revealed that the strain relaxation rate of InxGa1-xAs/GaAs thin films is significantly enhanced (over 20 times faster at 500 degrees C) by the presence of a growth flux. We have explained this effect with a model in which the energy for dislocation single kink nucleation is lowered in the presence of a supersaturation of adatoms. In this paper, we present additional measurements showing that the growth rate dependence of this enhancement agrees well with our model. We also address alternate explanations for these observations. (c) 2005 American Vacuum Society.