Maybe it's implied, yet the author didn't seem to care about fast, and mostly appeared to be counting whole numbers for greater lift. Guess most of the furthers probably also have uses if force is not an issue 1/3:1, 1/4:1, ect...
Sailing's not one I'd thought of much. Guess if large scale sailboats ever make it around again, hauling large scale ripstop nylon clipper sails might use a really fast spinnaker halyard.