I currently have 2 installs like that.And then in a couple of months, they can try the demo of BI and start down the journey of running both!
Many do that as you can feed the NVR into BI so the NVR essentially becomes a POE switch with redundant recording.
In both cases the cameras worked and looked great but the owner didn't like the clip review process in the NVR. One's an Amcrest NVR and the other a Zmodo.
Both BI servers were put in within a few months of the owner putting in the NVR.