There would be a lot of things that could be moddable... Actually, ideally there should be an editable txt with all the main variables...
The variables I'd like to see in a script (or an editable txt) are:
-Population growth rate.
-Advertising efficiency base value.
-Transportation costs base value.
-Mines quality base value/random.
-Mines quantity base value/random.
-Units input quantity/output quantity/capacity/processing speed/etc.
-Technology research time base value.
-People. Quantity, profile, expertise, personality, etc.
-Products stats. Neccesity index, % of price, brand and quality, etc.
-Production stats. quantity of input needed and final quality.
-City product stats. Price at which local competitors sell each article in each city.
-Training time base value.
-And a lot more...
And, above all, make the save files editable... (enlight should learn from paradox at this particular subject)...
Greets, and thanks again for implementing this feature...