Representing ice-shelf and ocean interactions in Earth system models (ESMs) has been severely limited by their coarse resolution and their fixed ice shelf cavity geometries. We have recently implemented new algorithms in the ocean component of the Energy Exascale Earth System Model to enable dynamic ice-ocean interactions within Antarctica’s ice shelf cavities. Here we present ocean simulations in idealized ice-shelf cavities modeled on the ISOMIP+ domain featuring active ice-shelf thermodynamics, a thin subglacial film below grounded ice, and high vertical resolution in the ice-shelf ocean boundary layer. We compare ice-ocean boundary layer properties and ice-shelf melt distributions in simulations with continuous dynamics between grounded and floating regions of the ocean model domain to simulations with fixed grounding line representations. We also compare these simulations with continuous ocean dynamics across the grounding line to those with either no fluid exchange or prescribed subglacial meltwater outflow across the grounding line. In light of these findings, we discuss considerations for the simulation of dynamic grounding lines in regional ocean models and ocean components of global ESMs. Given the sensitivity of ice sheet model projections to melt rates near grounding zones, we also discuss our findings in the context of melt parameterizations for ice sheet models and how observations of the grounding zone environment may play a role in validating these modeled melt distributions.