Its a good question, and here is the data I have (pieced together). We plugged into the Chademo at Geneseo at 6:44PM. As I had a free session from EA, I have the phone log in which they started the session for my from. As it was a free session, it did not show up in my charge history in the EA application.
We started at 16-17% on the dash. We watched it for about 2-3 minutes (it was at about 20%). The EA screen and the car both reflected the 53KW charge rate, so assumed it was accurate.
We then went to dinner across the street. I was checking my connect app every 3-4 minutes to ensure the charging continued. With each refresh it seemed to continue to go up 2% per minute, which seemed in line with my expectations at that rate. It was in the upper 70% when our meal came, so at that point stopped checking, as I only needed about 75% to confidently get back (161 miles to home at that point).
After we paid, we returned to the car, it was at 87% and showing the 20KW rate. I don't know how long it was at that rate. It took 5 minutes to get to 90%, which at that point I unplugged as we were now high enough I could drive without caring about efficiency. (the 60 - 80 acceleration curve on the car is quite crisp!).
The car was on the charger for just over an hour, as we got on the road at 8PM (65 or so minutes). I bought a coffee after the charge before getting on the road.
Its very possible it stepped down around 70% or 75% charge, as in the last 20 minutes (between getting food and paying) we only gained about 12% or so, which would imply a slower rate then 53KW.
% on dash are not completely linear, so this requires some salt.
6:44 - 7:25 17% - 75% (so ~36kWh which is about right as the timings are not exact)
7:25 - 7:52ish 75% - 90% ( ~9kWh, so a rate of 20KW or so average, which suggests the step down).
Sorry, I don't have anything more specific.
2019 SV Plus Silver
2013 Leaf SV
100 Mile Club Member (Number 87)
Max distance on 13 Leaf: 120 miles
Max distance on 19 Leaf: 242 Highway 4.5 miles/kWh (4.9 KWh remaining)