leafbike is the only company i know of who has published a dyno graph on any DD hub motor showing >90% efficiency in the 1500w motor.
Real world testing on the motor thread has confirmed it's capable of doing that.
YescomUSA is just an average mid quality clone of a clone motor and it's very unlikely to have excellent efficiency because low cost is the priority with those.
QS motors tend to be a little less efficient than average, probably due to copper end turn losses.
MXUS motors tend to be average, peaking in the upper 80's but never hitting or exceeding 90%.
The old cromotor was said to be very efficient but we don't really have dyno graphs on those.
It is unfortunate that there is nothing better than the leafbike 1500w in terms of hub motor efficiency. The leaf peaks at ~90.7% efficiency but with another, i dunno, $25 USD in materials, it could probably hit 92-93%.
Nobody out there in the DD hub world seems to care about efficiency much. Unfortunately the cutting edge designs are often found in shaft drive motors for cars, motorcycles, RC airplanes, 'n such.