What makes a tectonic system sensitive to erosion and sedimentation?

The notion that erosion and sedimentation help localize strain at tectonic plate boundaries is now backed up by two decades of numerical modeling. Key questions however remain regarding: (1) the physics that underlie this important feedback; (2) the main parameters that make a tectonic system sensitive to surficial mass redistribution; and (3) whether this feedback can be documented in real settings. I will address these issues through the perspective of extensional plate boundaries, using a variety of examples from continental rifts to mid-ocean ridges.