You wouldn't be able to accelerate that cargo e-bike to 28 mph even partly loaded. People often think the 28 mph is the promise. It is not. It is just a theoretical motor assistance speed limit.
What seems to be very strange there is the fact the Yamaha PW-X has never been a Class 3 motor...
P.S. Momentum website never mentions the e-bike Class or speed limit. Check the Momentum Bikes website for the United States. (I wonder how
@Court got that information).