there is a slight design flaw in feigoas integrated heatsink design that limits it usefulness somewhat.
On the 380c motors there are fins but nowhere for the air to escape or flow thus it would create an air pocket in-between these fins.
The bottom line is they tried to emulate the c40 and kontronik twist motors using and extruded section with fins for the casing but in the end this means the arrangement of the fins is inferior to that of the c40 and twist motors