The META-TOO proposal underscores the knowledge and skills transfer from two distinguished European institutions, the French National Institute for Research in Computer Science and Automation (INRIA) and Fundació de Recerca Clínic Barcelona in Spain (IDIBAPS), each renowned for its research contributions in the digital forefront, to the National and Kapodistrian University of Athens (NKUA), Greece, serving as the coordinating institution representing a Widening country. Specifically, both INRIA and IDIBAPS have earned global recognition for their outstanding contributions to Extended Reality (XR) research. It is precisely within this domain that we have elected to focus the support of INRIA and IDIBAPS, as “mentors”, for the National and Kapodistrian University of Athens, with a concerted effort aimed at reinforcing research management and administrative competencies, alongside enhancing research and innovation capabilities.