Don't mix your picture with my picture, that is also the physics picture behind LENR. The maximum amount of energy that can drain out of D*-D*, D*-A, H*-H*-A is given by the coupling magnetic moment.
I am not presupposing any particular mechanism for the LENR phenomenon. What I am saying is that if you contend that the rate of heat release from the fuel increases with temperature, then there should be an inflection/trigger point.
Roughly speaking, what shape do you predict for a plot the rate of the reaction vs temperature?