Dead spots are dependent on the design, materials, hardware and setup of each individual instrument, so there really is no one correct answer to your question. Dead spots tend to be caused by the sympathetic resonance of the instrument body and neck ending up out of phase with the string, which dampens sustain. Exactly where that happens depends on the instrument's sympathetic resonant frequencies, and that is dependent on the exact densities of the body and neck woods, as well as the dimensions of the neck and body. So, changing literally any of the major variables will change the behavior. The next question is, how, and how much, will a certain fix change the behavior? Again, because the issue is related to the interactions of specific pieces of wood and metal, it's difficult to say.
The ultimate answer is that if there's something else about the instrument that you want to change anyway, like a beefier bridge for more sustain overall, it certainly can't hurt to try, and in the bargain you might lessen the severity of the dead spot, or move it away from notes you commonly play. If you like everything about how the bass feels and responds except for the dead spot, be aware that any change you make can change feel, and if you don't want any change, the options are to live with it or look for a different instrument that feels as good without the downside.