With advanced software any heat transfer can be shown in a simulation based on some CAD design. Then you can also simulate different materials like magnesium and copper but aluminium is price and weight wise the best choice of material although there are many different kinds of aluminium with also different heat transfer specs. In theory the 2000 kind of aluminium is the best due a higher grade of copper.

Like my head with a so called tunneled airflow is seen more, a good example is a car radiator and the better brands processor cooling but also my HarmanKardon TC600 car amplifier has a tunnel shaped heatsink cooled by a fan blowing air through the tunnel.

Crankcase cooling is a bit done by the chassis plate, it is not the spot where the heat is generated but it does help a bit in the total cooling of the engine. The actual heat is generated within the sleeve with has the best cooling contact to the head due the 4 tight screws holding the head. I can remember the 90's with the 235mm 2wd class, back cover cooling ribs became popular but we also noticed it could give tiny issues with tuning. For a part the crankcase temperature does help vaporizing the mixture and so to cold or to variable cooled can have an influence on the tuning..