so yes I have one wisp remaining and I have no idea which one. I think it's down to one of five locations, as there wasn't a wisp there when I looked, and I think I ticked the others off as I went for the others.
i also accidentally discovered in sun/moon that IF YOU DIDN'T HAVE YOUR BOX LEGENDARY IN YOUR PARTY SOME ZYGARDE PIECES WOULDN'T SPAWN i think i checked every location like 6 times