From what I experienced in my break-in period, I'd say it's about 75% mechanical "conditioning & learning" and 25% driver C&L.

The vehicle does need some conditioning and learning to "dial in" to the best efficiency, but it does also take a bit of "reprogramming" of the driver to get the most out of the vehicle's technology.

I found most of the reprogramming of my habits was trying to figure out the tricks for how best to keep it in EV as long as possible and trying to figure out the pulse & glide tactic - that takes a lot of practice. It takes quite a while to figure out just how much pedal pressure you can apply but still keep it in EV. I actually found this to be fairly difficult in the first 3,000 miles because you're also kind of fighting the mechanical break-in of the vehicle while you're trying to figure this out. It won't let you get into EV very easily during the break-in period, and it gets to be frustrating at times. But once the vehicle has broken in it's fairly easy to get it into EV - by the "reprogramming" of both the driver and the vehicle.