We use PM to gather metrics for about 2000 network devices. We apply the Interfaces metric family to everything. We now have a requirement to do projections (bits/s) for some interfaces (big circuits). I dont want to turn on projection calculations for every device we monitor since that would probably hurt performance (300K ports). Does this mean I need to make a copy of Interface metric family and rename it, turn projections for bits/s on in the new metric, and then create a new (or copy the existing) vendor cert for each vendor of devices we want to apply the Interface_projections metric family to?