Almost always Remember that all large foils need some drag at the back end to keep them stabilized. The more drag, the more stability. That why we offer at tube tail package with the kites. Neither of these rules apply to large kites. We use thicker line.
Large kites have the power to lift it, and thicker line is easier to grab hold of.
For example, a 500 pound kevlar line would have a thickness less than a pencil lead. Our 500 pound line sleeved dacron is about as thick as the entire pencil. We also prefer line with a bit of stretch. But more important, we consider line-stretch on a large kite to be a safety issue. Better to have wind gusts absorbed in line elasticity than to pound your anchor until it breaks loose.