Nope - go for it. Just know the 'last registered' vR Ops will be the one that is registered in the vCenter Web Client.
If vR Ops is collecting from a 'fully loaded' vCenter Server, as in vCenter is at its product maximums (not many customer are!), you should see a maximum 10% increase in vCenter CPU (assuming the vCenter is sized properly). So, our guidance is to not have more than 2 vR Ops deployments monitoring the same vCenter Server. And be aware tat each vR Ops instance will have between 5-10 maintained connections to that vCenter Server. The # connections depends on the size of your vCenter inventory, and they're maintained user connections that you'll see in vCenter GUI.