Broadcasting services are continuously evolving, especially after the advent of full-IP standards like ATSC 3.0. Despite this rapid change, there are still daunting challenges to address. For instance, the broadcasting network can not be dynamically auto-configured, and requires continuous operation actions from Broadcast Network Operators (BNOs). However, the Broadcast Core Network, a new entity under development, will provide intelligence to this system equivalent to what is done in Cellular Networks, and what is more, it also opens a window to reach an auto-managed system. In a previous work, the authors proposed upgrading traditional transmission facilities with a Spectrum Optimization Software Module, which can dynamically add/remove/modify the services within PLPs. However, in the legacy solution, there is always some unused capacity as the media and PLP capacity are not 100% aligned. Therefore, this paper proposes a mechanism to maximize spectrum efficiency by inserting a new datacasting service in the available free space: an opportunistic PLP. The paper describes the practical demonstration that shows the potential of this new approach.