Does Fast Charging Ruin Your EV Battery? - TL;DW: Enjoy your vehicle :

[Vincent]

This is another phenomenal EE video, breaking down the battery chemistry and internal reactions.

For those who want a quick synopsis:
Multiple studies do demonstrate that *generally* DCFC fast charging does degrade battery chemistry faster than slower charging. HOWEVER, the significance is minute. AND there are multiples of caveats, insofar as the variability of affects are due to combinations of speeds, current and achieved State of Charge, climate (temperature especially) of the battery module and cells, and so forth.

When looked at extreme cases (a vehicle that exclusively fast charged in the Arizona desert) versus a vehicle that exclusively L2 charged, the delta over its lifetime was only 5%. And the realities are: with the evolution of EV tech (BMS, battery conditioning, and built in maintenance and sensors), it's really not worth splitting hairs over.

I've never really been worried about these things. After all: Rivian has a phenomenal 8 year 175k mile warranty on the battery and drivetrain. However, I do see much debate online for passionate owners that want to preserve the longevity of their vehicles, and that's admirable. The reason I shared this is: hopefully this helps alleviate that anxiety. JUST USE YOUR Rivian. Adventure awaits