Polishing may facilitate ejection. This applies generally to the finish of the core, including side cores, in cases where the product has projections produced by deep recesses in the cavity or where there is little draft angle specified, the cavity must also be free of any roughness that prevent easy ejection.
your suggestion is correct, polishing process is very important in mould making
yes! it is correct, but sometimes some mold workers easily ignore it, especially for beginners