The usual expectation in the solution of a fill section is that the target surface is being approached from above, and the expectation in the solution of a cut section is that the target surface is being approached from below.
I have seen solutions that violate these expectations, and they're disappointing to say the least. And correcting these means setting up a somewhat convoluted set of conditionals for each major cut or fill section. A built-in conditional would be much smoother to use and include in all appropriate templates.
