and Demandred thinks "Entire cities died in balefire that year, hundreds of thousands of threads burned from the Pattern."

Though it does seem that the properties will adjust to what the plot requires. Or perhaps to what the user intends; there are a number of weaves that essentially do what the weaver wants done without requiring the user to calculate what to weave with an abacus. (Triangulating a place to Travel would be a piece of cake next to side effect-free Healing)