Copied from the comment section of the link at the bottom of your post, here is a response from Phil Trubey:
“Interesting that the Tesla megacharger is a lot more efficient than the Kempower one. They both output about 1.2 MW per post, but Tesla only requires a 2,500 kVA transformer for two posts, while Kempower requires a 3,000 kVA transformer.”
Does anyone know if this claim is true?