You might be able to get it this effect with subsurface scattering (or two sided foliage, if they repair the opacity slot for it), if you blur that “Grid” texture manually and bring it into unreal. Or if it is an actual mesh, then you can test, how it´s shadow affects subsurface materials.
I don´t have the old Ent, but i tested it with the Ent-D, and it can look quite good. Colors then depend on the main color for the surface, but even more on the subsurface color (the shining through color), and the light color, from the lights, that shine from behind.
Subsurface and twosided foliage are pretty similar, so test, which one is less buggy at the moment ^.^
That raytracing quality switch is just there, to make those subsurface materials visible in raytraced reflections, because until now, subsurface and twosided foliage results won´t be reflected by raytracing. But it turns out, you can trick it with this switch to reflect something different than what the camera sees. The camera sees, what you actually see on screen, the result of subsurface scattering effects and lights and color etc., while the reflection rays hit that linked red color only (could have linked the color with the opacity texture mix, but the hull isn´t shiny, so doesn´t matter). You just have to manually match it with the light intensity etc., so that their reflections look fitting.
