It would be nice to have the “Visible to GI” checker box from VRay Object properties inside the VRayMtlWrapper material.
As a workaround I think this can be achieved by using the vrayoverride material and set the GI material to a material that is 0% opaque (using the opacity slot, not refraction). This way it’s still in the material and not the properties. I’ve done it this way in the past.