True, but math isn’t physics. 
The issue with the motor is not the running draw rate of 2A, but rather the inrush current when the motor starts up.
This is rarely a problem with a simple on/off extractor fan. but it is often a problem with any variable speed fan, because the physics are different, and inrush current is insanely high relative to the running draw.
This is why Zooz has their warnings about fans, but it applies to any brand not manufactured to control a variable speed motor.
I can find a number of people in their 80s who have smoked cigarettes every day for 65 years and don’t have cancer. That doesn’t mean that smoking doesn’t create an increased risk for cancer. So anecdotal reports about someone who hasn’t had a problem doesn’t change the specification. just sayin’…