This paper presents a methodological exploration in postcolonial HCI. We share early insights of designing a digital platform for Indigenous nation building in Australia that speculate ways to catalyse, provoke and support necessary discussions of governance, plurality, cultural integrity and knowledge ownership. Rather than expecting consensus building or striving for problem-resolution, prototyping this digital platform has begun revealing tensions, complexities and possibilities that are significant to nation building. Manifesting and actively debating these became an epistemological pursuit for knowledge generation, but also a necessary ontological one in actively carving out 'agonistic' engagements that challenges hegemony and practice ploy-vocal future-making.