This “Final report on MAX in the European, national, international HPC ecosystems” offers an overview of the activity of MAX European Centre of Excellence (CoE) as an actor of the HPC European and international ecosystem at different levels. All the activities are aimed at addressing technical and policy issues of pan-European relevance, promoting synergies and helping to overcome the fragmentation of European HPC activities on applications. This report focuses on the period June 2020 - September 2022, and first describes MAX interactions and joint initiatives with the main European HPC actors, especially the CoEs ecosystem –including the other CoEs and their coordination instruments HPC3 and FocusCoE–, and the EuroHPC Joint Undertaking as a whole, as well as the main European organisations and projects in the field of HPC infrastructures, data and technologies –including EOSC, ETP4HPC, EPI, and PRACE–. Beside general coordination actions, we held dedicated meetings with representatives of the relevant HPC Consortia in order to best take advantage of the new EuroHPC supercomputers –especially the pre-exascale machines– since their very beginning. MAX plays a leading role in its specific domain of materials research, and has strengthened its long-established collaboration with the relevant stakeholders. We report on the activities with the Psi-K network, CECAM, EMMC, the Battery2030+ and BIG-MAP initiatives, OptiMaDe, as well as some other relevant initiatives at national and international level. The richness of these interactions has required significant effort from the management and all MAX partners. We believe that this investment has contributed to a more coherent, effective and friendly ecosystem in Europe, and to positioning MAX at the front of the European and global landscape in the HPC materials research.