Prior work has shown that the integration of Kubernetes orchestration tools with present Network Functions Virtualization infrastructures toward Cloud-based 5G deployments may be the key to unlock beyond 5G communications. However, before we reach that point, further work is required to define, implement and validate practical Cloud-native augmentations that will enable virtual network functions management and orchestration via Kubernetes architectures in existing 5G platforms. In this paper, we present our approach in the context of the 5GEPICENTRE project, drawing from ETSI-compliant reference implementation frames in order to enhance an experimental 5G testbed with capacity to host containerized network applications. We study how the proposal can be used to validate key performance indicators on high-demanding 5G applications, such as those characteristic of the Public Protection and Disaster Relief vertical.