As Jean-Pierre mentioned, VI Server knows whether a VI reference was opened strict, and it uses this to know whether you can or cannot use a CBRN to invoke the VI. What I suggest that you do, is open two seperate references: one strict, and one non-strict. Use the strict reference, only for validating that the VI's con-pane is correct (matching your plug-in conventions). Use the non-strict reference to invoke the Run method. Make sure that both references are opened before closing the strict reference, or you may incur the overhead of loading the plug-in VI into memory twice.
BTW, why are you not using the CBRN to invoke the plugins? If you are enforcing a strict con-pane adherance of plug-ins, then this might be the best approach.