In Verdante map, feeding Stone Hatch aluminium ore does not increase their chances to lay a Smooth Hatch egg. Tooltip says only copper ore, gold amalgam, iron ore and wolframite can do that. Sounds like a bug rather than a feature.
Conveyor rails uses 100 metal ore to build. Whilst conveyor bridges takes 100 raw minerals to build. Exploitable to build conveyor systems using just conveyor bridges and connecting bits of conveyor rails which (in my opinion) is probably not what the developers intended.