Versatile augmented reality (AR)/mixed reality (MR) technologies align with custom manufacturers’ resource constraints and support their requirement for agility in responding to unique Industry 4.0 challenges. However, for Australian custom manufacturers, AR/MR uptake remains low. This modest-sized case study seeks to support resource-constrained custom manufacturers by exploring current AR/MR adoption challenges and potentials. Underpinned by a Research-through-Design (RtD) methodology and building upon Situated and Participative Enactment of Scenarios (SPES) methods, we reflect on using novel Microsoft HoloLens 2 AR/MR mockups to support in-situ enactments with domain experts to collaboratively imagine and design more productive and efficient augmented fabrication and assembly practices. In exploring new ways of making and doing through AR/MR, we find promising pathways for Australian custom manufacturers to add value across a product’s lifecycle. Our findings identify five key areas for further research, which will be explored and developed through workshops around each identified AR/MR application area.