It would be really neat to see the OPC server object have a checkbox for something like Block Controls or Ignore Writes. The use case for this is when there's a production system and a second system (QA or Dev) pointed to the same OPC server. You can have the OPC server object in QA configured to ignore writes that way all other features continue to function without impeding with production data. Often times we have customers who want to see values updating in development or QA to replicate load and other things.
We could use server denied permissions and block control, but we still want logic and ST to continue to work so I'm not sure there's a workaround for it.