The lower shoreface, a transitional subaqueous region extending from the seaward limit of the surf zone to beyond the closure depth, often serves as a sediment sink or source in sandy beach environments over annual to millennial time scales. Despite its important role in shoreline dynamics, however, the morphodynamics of the lower shoreface remain poorly understood. This knowledge deficit is partly due to the absence of sediment compositional data across the seabed and to the challenges inherent in measuring subtle bed changes (mm-cm/yr) over historical time scales. It is also unclear how diverse lithologies and long-term changes in wave climate influence shoreface morphodynamics as previous work often considers these steady-state systems in equilibrium. To better understand the controls on shoreface dynamics, we extend an existing energetics-based framework to model sediment transport across theoretical shoreface equilibrium profiles under various physical and geologic disequilibrium conditions. We further incorporate varying shoreline input flux scenarios (i.e., accretion, erosion) to investigate potential coastline inheritance controls on shoreface evolution. Equilibrium profile shapes and disequilibrium sediment transport rates are more sensitive to changes in sediment settling velocity than wave period, indicating that grain size provides a strong geologic control on shoreface morphodynamics. We find that at depths greater than 20 meters, shallow water wave assumptions predict larger sediment transport rates (~1-8 orders of magnitude) than linearly shoaled waves. Furthermore, for linear wave theory, we find an abrupt, discontinuous offshore transition where the bed response to changing wave climates becomes exceptionally slow. Our results provide insight into the sediment dynamics that drive the spatiotemporal evolution of the shoreface, improving our understanding of the interactions between onshore and nearshore processes and geological inheritance.