Why do LFP packs still taper so hard above 80%?

I daily an LFP car and love that I can charge to 100% without guilt, but the DC curve still falls off a cliff past 80%. On a 150 kW charger I'm down to 40 kW by 85%. I get that lithium plating risk rises near full, but LFP has a flatter voltage curve, so the BMS is basically guessing SOC at the top end. Is the taper mostly protecting the cells, or is it thermal and BMS conservatism? Anyone seen faster top-end curves on newer LFP packs with better reference electrodes or smarter charging algorithms? Curious what real-world data people have.