Screening numerically internal fluidic injection scenarios for the manipulation of the double diamond shock pattern in convergent-divergent nozzle exhausts, we demonstrate the individual importance of design parameters. We find that the evolving shock pattern is sensitive to the injection location, while the persistence of the induced counterrotating vortex pairs is primarily governed by the injection pressure. Injection close to the nozzle exit generates secondary vortical structures amplifying the fluctuations in the nozzle vicinity.