I agree with jcanoe... I'm not an expert, but I've only heard the factors that degrade battery life (maximum State of Charge) over time are: high temps (like battery preheating for supercharging), keeping the battery long term at very high or low State of Charge (%), and charging/discharging faster than 1C (1C is ~77kW for a model Y).
Bjorn Nyland had a good video on it here:
. His observation is that a majority DC-charged car had 6% max SoC degradation but a majority AC-charged car had 4%. But not exactly controlled variables nor a large sample size. The deciding factor in the video I think was probably high C + Supercharger preheating rather than DC vs AC.
For optimizing battery life on a model Y, 50kW on a CHAdeMO is probably the second best option for charging, only a 72kW Urban Supercharger is better. Free CHAdeMO are rare, I've only ever seen them on ElectrifyAmerica stations, where the $/mi ends up being close to gas. Use it! lol. Just charge only what you need to get to the next charger and a safety buffer, to keep near 50% SoC.
Someone correct me if I'm wrong.