Just want to update this with a couple of possible solutions which have come to light, the first is to add a custom code node with the following code:
#if(SHADOW_DEPTH_SHADER)
return fShdw;
#endif
return fAll;
Inputs being: fAll and fShdw
and set up like this:
Alternatively, this method also seems to work:
This can be a little bit more rough around the edges though, and the Fresnel might change depending on where the mesh is on screen .
more info can be also found on the [Forum Thread][3]