In competitive industries, intensive and repeated innovation is a recognized necessity (Wheelwright and Clark, 1992; Le Masson et al., 2010). Literature on innovation (Utterback, 1994; Henderson & Clark, 1990) distinguishes Dominant Design revisions (radical innovations) from local improvements (incremental innovations). Regarding the innovation process management, one success factor lies in the knowledge articulation between front end and new product development (NPD) stages (Koen et al, 2002; Cooper et al, 2001). Then, central issue becomes NPD stakeholders' management (Elias et al., 2002) and their ability to establish perennial learning dynamics across the two parts of the organization (O'Connor, 2008). Our paper fits into this research field for local innovations on the dominant design. We discuss the role of technical expertise level of NDP stakeholders involved in early stages. The research mobilized two longitudinal studies (Yin, 1989) carried out with a global car manufacturer since 2005, one focusing on the innovation management process and organization, while the other was devoted to learning dynamics of engineering development departments. Leading as collaborative management research (Hatchuel and David, 2007), analyses were enhanced through deep interviews with project managers, technical experts and decision-makers. Analyzing local innovation impacts, we find that effect of breakthrough innovation projects on NPD organization was similar to waves: close expertise are quickly and strongly affected while distant expertise are more weakly and later affected. Our research material shows that tracking of key stakeholders is based on functional division of the organization whereas force and temporality of the innovation impact could potentially follow other propagation logic. Stakeholders identified by the organization as key actors could be in reality weakly impacted but we observed they were able to convey useful knowledge to heavily affected actors inside their organization when they had a high level of technical expertise of the dominant design. Expertise robustness plays a screen role that returns, as an amplified echo, the innovation low impact on their technical perimeter toward those heavily impacted.