Are you certain it's not just between USB power and Vin?
Yes, look at the schematics. It is an M7 diode. That has a maximum forward current specification of 1A.
Measured the current it's 2A for an hour nothing got hot besides the motor.
It is not just heat that kills a component due to over current, it is things like carrier depletion and thermal stress.
So you diode will die long before it's time is due, because you are over running it by 100%. Not a thing I would recommend.
It's like all the people who smoke and say "well I am not dead yet".