I'm not familiar with the latest research, but the WAIS has long been recognized as the biggest potential contributor to severe sea-level rise due to the marine

I'm not familiar with the latest research, but the WAIS has long been recognized as the biggest potential contributor to severe sea-level rise due to the marine ice-sheet instability, which it is uniquely vulnerable to. Ice sheets are basically big domes of ice that flow outward under their own weight. Little surface melt occurs in Antarctica, while snow continues to fall. To maintain approximate mass balance, most of the mass is lost to the ocean. Most of the WAIS bed is below sea level, but the ice is thick enough that the ice rests on the bed, and seawater is excluded. Where the ice sheet begins to float is where ice shelves or calving happens. Towards this margin, the outlet ice streams are almost but not quite floating. They have little friction at their beds, but they push up sediment in front, forming sediment wedges that push back on the grounded ice behind them. This slows the outward flux of ice, and creates a stable equilibrium as the ice pushes up against the wedge. Much of WAIS is on a reverse bed, where the bed drops in elevation as you proceed inland (despite the ice getting thicker, and the top of the ice sheet getting higher and higher). Due (largely) to increased submarine melting leading to thinner ice shelves (which themselves push back due to pressing up against islands and such), the ice grounding line can retreat from the wedge. Worse, this enters a feedback: due to the reverse bed, the ice is now thicker in the new retreated grounding line, because flotation occurs in deeper water. This increases ice flux due to the thicker front. Thus retreat accelerates more, and so on until the ice sheet collapses.