> the curve has no cofactor The groups do have a cofactor of 2 ("Curve order must be equal to 2r for a prime integer r"). When they say "There is no cofactor t

> the curve has no cofactor The groups do have a cofactor of 2 ("Curve order must be equal to 2r for a prime integer r"). When they say "There is no cofactor to deal with", they mean they pick a generator that's divisible by 2 (like G=(2,2) in do255e) and use curve point representations that only allow multiples of G.