Hi didsy;
I use to do Small Universe and holosync together but these days just do them seperately. I have seen a few posts of doing Small Universe while watching TV or walking or whatever so there is probably nothing wrong with doing it. I didn't have any negative experiences during holosnyc and small universe.
Although what I believe is the big difference in doing Small Universe by itself is being able to go more deeply into the emptiness with no distractions. This is where you get a better pay off for your time.
hope that helps.
Jeff