TL;DR
Introduce fallback replacements for recipe ingredients.What ?
Allow some resources to function as replacements for other resources in game recipes. Like feeding steel into your assembler instead of iron, red circuits instead of green, or metal ore instead of stone.For more esoteric products (like science packs) might allow even greater variety of possible ingredients while maintaining overall cost (like allowing liquid ingredients for red/green science).
The overall objective is to allow player more freedom with how to design the factory. He might be able to use a plentiful resource, or just one that's available locally, getting around local shortages. Additionally, supply can be simplified (just feed blue circuits to your factory instead of green/red/blue in specific ratios) at the cost of resource expenditure.



