You'll never get any real performance from a hub type electric bike! I've ridden them, they're dogs!
The E-bikes that performed well at the motorized bicycle races were full on custom race bikes built by guys who really know their stuff. (& also had some big time coin into them.)
& I don't care what the 4-stroke guys say... Pound per pound & dollar per dollar, you'll get the most bang for your buck from a 2-stroke.