This paper proposes a flexible data frame forwarding scheme that effectively works to achieve advanced data exchange services in the future IoT systems in Beyond 5 ^th Generation (5G)/6 ^th Generation (6G) era. The proposed scheme employs a recommended practice of IEEE 802.15.10 specifications that were standardized for an effective control via Layer 2 Routing (L2R) in the IEEE 802.15.4 personal area network systems and conducts data frame replication and concatenation functions according to the diversified demands on the assumed IoT services. The proposed scheme is also expected to become one of candidate technologies that is equipped in the future IoT testbed structure in order to evaluate the future complicated and diversified services. In this paper, performances of the proposed scheme are evaluated via the fundamental computer simulations and the field experiments deploying the developed L2R radio devices. Consequently, it is confirmed that the proposed scheme can improve the data exchange performances among massive IoT devices by improving the performance of frame success rate about 40% from the conventional L2R operations.