LS2/Sok 338a "curvature" reflects a total misunderstanding and failure to read the passage. The meaning of the passage cited there is simply "customary behavior" as elsewhere. Interestingly, this passage in not cited by Brockelmann in his addenda where he adds this meaning; but neither of the passages there cited support this meaning either! The first is also "habits" and the second is a quite different word altogether. Caveat Lector!