Time stamps are off in Illinois. Showing a 10pm last charge, then a 1am next charge. Wonder if that's an EST/CST thing happening there.
Nothing weird happening - from 10:23pm (end of Illinois charge) I drove 2 hours 38 minutes and then started charging at 1:03am. There is some rounding happening, but no time zone issues.
I was using the "Power Used" number from your screen shots. Is that power that the supercharged used, and "Power Added" is what actually made it into the car. So the efficiency listed is not that of the car, but that of the supercharger? Seems like a weird thing to report, although I guess if you're paying for the power pre-charger, then you want to know how much is wasted to heat. Right?
It's somewhat irrelevant data (even to a math geek like myself) but yes, the efficiency shown on the charge lines is the kWh drawn vs the kWh that went into the battery.
I'm guessing since I don't know how much you actually used (only what was added), and you could potentially add more than you used (assuming you start low, use some, then charge to higher than where you started) I don't have the info to calculate whr/mi....(which seems unfortunate it doesn't log that as well).
You can get to it by using the SoC at the beginning and end of every charge session, but it's really not that important - I gave you the info above.
What's the story with not charging to 100% each time. I get the effeciencies are poor at higher states of charge, and current is limited to protect the battery pack and all that, however the ICE mentality suggests that you always charge to 100% (or fill up) at a charging station. I'm curious how you get past the mental hurdle of pulling away from a charger without a full tank. I can't imagine going to the gas station on a road trip and not completely filling the tank, only trusting that I'm going to carry what energy I think I need to make it to the next stop. The boy scout in me says that's a good way to find yourself unprepared in moderately unknown territory. I mean, clearly it works just fine, it's just some mental gymnastics to get over on my side.
It's probably one of the biggest hurdles when you road trip with an EV, I still know people who "overfill" by 25% just to be "safe." The car gives you so much info en route that you can ALMOST always plan a 5%-10% buffer (which you can see is my target). The only risk I see is if an accident occurred that caused a 25+ mile detour DURING your leg. Remember that the car is using current traffic info so if a portion of the highway is closed before you start the leg it will route you via the detour and tell you to charge more (I have had this happen). Even if it happens while you are on the leg, your average speed is going to drop so heavily, causing your efficiency to go up so dramatically that you will probably have enough.
Adrianp89 answered about the taper, but here's the most I've ever charged at a Supercharger (from 6% to 96% - I don't recall why) so you can see that in this case the charge rate was highest until the battery hit about 40% then it started to slow down. I typically keep that battery between 5% and 70% if I'm trying to minimize my total travel time.