Getting the appropriate equipment proved to be a major hurdle for the Dutch authorities..with some of the operators and/or manufacturers dragging their feet.
For some of the older aircraft it was not a question of a "plug and play" feature, exacerbated by bean counter mentality in some quarters.
The whole point of triangulation is to give adequate traffic information to offshore ADS/B equipped helicopters with regard to non-ADS/B but squawking crossing traffic in the busiest and largets part of the area, both civil and military. At the far edges of the FIR the risk of conflict with non-offshore traffic is small and the ADS/B provides the basis for Alerting Service/Flight watch.