Then it’s just a mather of asking the right person to fix the quantities before doing the closing.
Ok that make sense for me, so a warning should work for all cases.
As the quantities are used for the stock valuation (which affect accounting), I think it’s a good practice to make the user aware that there is something to be fixed.
It makes more sense with Add wizard to account the stock valuation because we require the user to close the stock period before creating the right stock moves.