A question that I have - which I have not seen or answered - is if I build something that is in the lower levels, but scrapped in the upper levels, will this work? Or is everything stackable. Meaning if a lower city level has x, y, z (not related to plots but build items), will it always be there in the upper levels?
If stackable, then regression seems to be the best way to account for these items? If things are scrapable, then progression (except plots as
@NDCowdy mentioned) would be the best way.
John