This qualitative study investigates the integration of the Dominant Language Constellation (DLC) framework into English as a Foreign Language (EFL) instruction in Israeli elementary schools. Through a seven-month professional development course, twenty in-service TESOL teachers participated in workshops employing reflective and visual methodologies to explore their multilingual identities and develop DLC-informed pedagogical strategies. Data from pre-course surveys, workshops, online discussions, and interviews underwent thematic analysis. Initial findings revealed participants’ unfamiliarity with plurilingualism, despite its inclusion in Israel’s New English Curriculum. Four primary themes emerged: Teachers reconceptualized multilingualism from an instructional challenge to a pedagogical resource; three-dimensional modelling facilitated an understanding of complex linguistic relationships; participants developed cross-linguistic strategies that enhanced student engagement; and teachers strengthened their professional identities as multilingual educators. Implementation challenges primarily involved curricular constraints and time limitations, with a minority finding the framework overly theoretical. The findings demonstrate the value of the DLC framework in bridging plurilingual theory with classroom practice through visual methodologies that materialize abstract linguistic concepts. Future research should expand sample sizes and incorporate classroom observations to validate instructional changes across diverse educational contexts.