They still matter. Granted, an endless loop string won't come apart if there are no twists in it. However, a few twists are usually still a good idea to spread out the tension in the string across all the strands. Otherwise, if one or a few of the strands aren't the same tension as the others, entirely possible if the string maker isn't careful, they do all the work. And, too many twists in an endless loop string will also contribute to excessive stretching/elongation while the bow is strung. In short, it won't hold its brace height. Rather, the brace height will inordinately decrease over time if the bow is left strung.