I sometimes allow cells to show error because formatting the cell to show nothing when processing an error may not show there is no formula. Which means you can forget how far the formulae go down. And blithly extend the data set past the row that ends the formulae.

Using a visible character instead of blank does complicate the formula, which is harder to debug as you change the data they are handling - eg numeric/non-numeric. In essence you can forget the original thinking/purpose of cells.

Keep it simple.