Well this dDo thing it's a lot more tricky than i thought , very powerfull but not that easy to figure out.
They made available to download a couple of models that they used in their tutorials. I tried to import the AK model in OT to have an idea of how the maps rendering would translate . I was a bit worry about the reflectance map (metal effect) but by setting the F0 to 0.45 i could use their specular (metalness) map as is. So all in all, the visual in OT is not too far from their 3do renderer .