Everything I say remains speculation as I have not experienced this situation so I can’t lie and say my answer is made with absolute certainty. In theory this would actually increase the connection to the famulus by uniting her with the various aspects of consciousness which remain outside of the Altar of Sacrifice. (My term for the heart chakra) In theory this would occur by default because the darkness consumes the separation which binds the potential of the chakra’s and not the chakra’s themselves. Remember “black” absorbs while white reflects.Therefore it would not make sense that the Kunda Yoga would push out or drive out this familiar. It does not even do this regarding the Amesha Spentas or Angels of the current. The purpose is to unite the separated levels of consciousness which equate to, and are attributed with the isolated colors of the light spectrum.
I hope this helps as this is a rather interesting question which I have yet to gain experience with however I have an automatic and intuitive connection to the Ahrimanian impulse and I do not see the Path of Smoke acting as a threat to something that is of service to your ascent, or as I prefer to say… the expansion of consciousness.