When the parameters that will be unlocked by the compact console are enough for you to visualize, then you don't need the viz-key. In this case, you can use Art-Net or sACN to feed capture with the DMX data.
If you want to patch more parameters as the compact console will grant and you want to visualize them all together, then you have 2 options:
1) Take enough processing units into the session with the compact console.
2) When you don't want to use the processing units in this case, then you need the viz-key.