In reply to cgales:
Exactly! And in hierarchical designs, one will have monitors on internal busses, without drivers. So the monitor has to be able to function without the driver being active.
Also: since those monitors will be attached to internal busses: put any assertions in the SV Interface code, so that the assertions can be active on those internal busses. If you put assertions in the driver, then they can’t be used except at the primary IO of the DUV.