Extrapolating from googled threads in EV and battery forums
discussing translated presentations and technical papers.
All technical research
docs assume 1C charging is just completely unrealistically slow, 45C and even higher charge rate targets are the norm.
The key question is framed as "how can we reduce the longevity hit? assuming fast as possible charging is required not an option".
And sophisticated thermal management systems are apparently the key at the cutting edge, within current
chemistries and manufacturing methods.
I had thought mainly oriented toward accommodating freezing ambients, and removing internally generated heat, but lot more too it than that, basically keeping cells within a tight temp band optimal for the current
usage (vs just sitting) mode.
Assumptions that LFP has similar chemical reactions, correlation with temperature trends as the more mainstream LI chemistries in that high C-rate world, make tight quantifications like you propose unrealistic to expect hard evidence, except by our experimenting ourselves.
Bottom line for longevity conclusions:
Low charging C-rates by default, especially when temps are cool do **not** go to high rates,
pre-warm the cells when fast charging, only if short charge times are really needed, still a longevity hit, the higher temp just reduces it.
Warmer temps also make a huge difference for high-C discharge rates, but more of a performance issue there, not as big a longevity hit.
Go cool as possible, and low SoC, while **not** cycling, only allow high temps and charge up to higher SoC ranges just before discharging is required.
Purity of chemistry is also critical QA build quality factor, impurities drastically cut cycling longevity,
I think this is a huge difference between the big respected brands and random / generic cells, besides just cell consistency in general.