Research about modeling emphasizes the importance of heterogeneity in science learning. At the same time, a growing body of scholarship seeks curricular pathways for epistemic and representational convergence. In response to this tension, we propose two constructs: heterogeneity-seeking curricula and commitments. Heterogeneity-seeking curricula emphasize generating and valuing multiple representations of phenomena, offering an image of science that foregrounds messy, nonlinear aspects of learning. Commitments parallel epistemic cognition research by focusing on values that shape students' modeling; however, rather than looking for disciplinary practices in students' modeling, commitments take students' values as a starting point, mapping them to disciplinary resources not typically foregrounded in science education. Using a lens of commitments, we analyze six implementations of a heterogeneity-seeking 6th grade modeling curriculum, and we compare the lens of commitments to the lens of epistemic ideals. Then, we show that, in this context, commitments functioned like epistemic ideals by acting as evaluative resources during modeling. However, commitments also extended beyond this role by helping students ask and explore questions that were not anticipated by the curriculum, problematizing a view of phenomena as objective and external to students' modeling work and showing them instead to be a production of the classroom's multidimensional modeling discourse.