Thank you! Glad that you enjoy the mod.
In the tips & tricks menu you can find the 'Economy' entry in the colony builder section which explains the supply and demand mechanics.
Unregulated supply is always used up first and does NOT generate coin, any demand that's left over is then fulfilled by Supply and that DOES generate coin. Any Demand that is left over will consume Coin, meaning you actually lose money. Any Demand that cannot be fulfilled with cause an economic collapse, which floods the economy with Unregulated supply.