I haven’t found it in the owners manual, but what, if anything, is the downside of operating the car at high speeds in the “L” setting. I’ve done it numerous times and the only thing I’ve noticed is a very slight and momentary surge when shifting to “D” at speed. I love one-pedal driving for local driving, but it seems unnecessary for highway driving.
No, no difference. Any speed, any period of time it will be OK.
Difference is at slowing down, especially at lower speeds, or to a dead stop. L would be overall more efficient as it does not utilize friction brakes, only regenerative braking.
Cruise control will behave same. Not that I noticed any difference.
As for the surge.
It has to do with different mapping of the accelerator pedal.
When in D 100% of the pedal travel is for acceleration, in L about 10% is reserved for braking. Hence, the remaining 90% is acceleration. That means that if you are at 17% power in D, it will be about 11% in L. I am making those numbers up right now, only for the purpose of presentation here.
You get the idea?
Same the other way, if you are at say 5% in L, it will become 10% in D. Or 0% in L (balance - free coasting), shift to D and it will accelerate. And so on...