Most of our intuitive knowledge is from experiences with hydraulic brakes.
Air brakes have their own particular properties.
Most manufacturers do not recommend resurfacing brake drums. On the other hand, turning or cutting a drum to remove small surface defects and heat checks may improve performance. It is critical that the drum in kept within the maximum diameter limits. The issue of turning brake drums to greater diameters and compensating with oversize lining is a confusing one for mechanics who also work on hydraulic systems. Hydraulic brakes systems with their adjustments for shoe positioning can compensate somewhat for oversize drums.