There's no theoretical reason why it can't be good. The Tesla Semi is capable of significant regenerative braking capacity over long downhill stretches. Tesla's

There's no theoretical reason why it can't be good. The Tesla Semi is capable of significant regenerative braking capacity over long downhill stretches. Tesla's marketing claim featured a route which included Grapevine Mountain — which has a 4136ft elevation. They assert that it was capable of continuous regenerative braking, though it's not clear how much friction braking was involved. (It's almost certain that some trailer braking was involved for safety and stability.)