https://www.avient.com/knowledge-base/article/what-s-difference-fillers-reinforcements
The thermal conductivity of conductive plastics is not as high as that of metal, but conductive plastics can be just as effective as metals in thermal management, transferring heat by conduction (which depends on the material) and convection (which depends on the design of the system and the flow of air or liquid around the polymer part).
All vents should allow trapped air and gasses to escape to the area outside the mold.