[Andrés]

I've heard many times some experienced modders say that roman numerals determine or are one of the factors that determine what is upgraded into what.
AFAIK that is wrong, upgrading is only determined by family and research, roman numerals only change the numeral is displayed the mini picture and have no other influence.
For example engines and high-energy weapons go back to 1 in roman numeral and they seem to be upgraded properly (changing the name and abilities/damages, but not family or tech area).
Has anyone tested this further?
For example make a component that has its roman numeral grow down istead of up and see if its upgraded properly?