Hi
Thats how most people do it when retraining the Tivo, the Tivo only needs one feed to the 3 internal tuners, as long as your signal is good enough and you don't introduce noise back into VM's network then it will be fine. A signal quality issue normally shows up as pixelation/picture break up, if not seeing any of that then it should be fine. If your paranoid then you can change the box name so if VM log into your router they wont see a zgemma h2h.