Bonded or riveted brake shoes??
I doubt that the rivet recesses in riveted shoes will help cooling as there is no air flow over them when the brakes are applied as the shoes are tight against the drum whereas drilled discs are out in the open air. It has more to do with lining quality, as previously mentioned. As a rule riveted lining is better quality than bonded lining. All new vehicles with rear drum brakes come with riveted lining. Look at the edge of the lining on a new shoe, from the side. You should see a code stamped on the lining which has to do with the friction characteristics of the lining material; whether it grabs better hot or cold, hardness, wear characteristics, etc. Deciphering this code is tricky as information is hard to get. Parts books usually don't have it. Calling the manufacturer or an Internet search may help. I have seen bonded lining come partially loose from the shoe and make the brakes extremely grabby.