My 16yo daughter (who I forced to take Auto Shop I because she's blonde and now she's enrolled for Auto Shop II because she really liked it) asked me how much energy was recovered through regen. I couldn't answer because I have no way of knowing given the current displays. The display shows energy going into the battery (in that energy flow animation) but it doesn't show how much. Further, the amount of energy used display does go down when you're regenerating energy, but nothing accumulates that over time.
I think it would be interesting to see the "total recovered energy (in KWh)" since the last full charge on that screen.
Maybe I'm making this up, but I seem to recall about 10% recovered energy during a trip is expected.
An example: I travel 40 miles on a full charge. We know that at the end of that, a total net of 10.2 KWh of energy has been used. However, during that 40 miles of travel some amount of energy has been recovered by regenerative braking. How much is that? Well, let's presume it's that 30% number, so a total of 10.2/.9 = 11.4 KWh was consumed, of which 11.4*.1 = 1.1 KWh was recovered energy. In this example, that number would go up by about 0.1 every 3.6 mils, on average, which seems interesting enough to be shown.