On the topic of Main Hoods and Downtowns (and trying to change them)

So “renaming” a Downtown neighbourhood (in that case meetmes’ alternative Downtown template) to turn it into a main ‘hood does not work? Atleast for me. After loading it once, it just disappeared from the neighbourhood display. It’s still in the folder, though (and yes, I checked if all the data has the same NXXX-in front of it). So I guess that’s just how it works? Or is that actually possible and my game is turning into a big fireball?