I know some places have laws or guidelines that tell you to put the flat pretty side facing out, but every fence I’ve ever seen, including the one I’m looking at out the window of this business I’m at now has the flat side facing the property and the ugly side faces out
No. You just put the nice part facing the one who paid for it and so you can paint it and keep it looking nice. Let the neighbours have the ugly side. They can build their own fence if they want.