With their new rules werewolves can watch the twilight spirits automatically and see them. Regardless which senses they actually use.

Now my question is though what does that mean if it comes to the Duguthim?

As far as I always understood the Duguthim are different as the Spirit is no longer part of the twilight but instead merged with the host. Do werewolves now automatically see that someone is a Duguthim and how the actual spirit looks like or not?