Fix transulcent material or fake refraction in masked material

is it possible to fake refraction in masked materials? I´m trying to do the predator invisibility effect with a stepvalue node to animate the transition in wich I erode the color channel, with the same node + a oneminus node I´m appearing the refraction channel. The method works but the transulcent material look with the two sided option has a really weird overlay. On a masked material the overlay goes away but I loose the refraction channel . I´m attaching pictures of the material