Authors - Harsh Sudhir Shah, Ozlem Mis, Bosen Zhou, Christian Zimmer, Frank Feinbube Abstract - Immersive digital twins use virtual reality, augmented reality, and Internet of Things technologies to create interactive virtual replicas of physical assets and environments that users can enter and explore. Across Europe, experts report only limited progress toward immersive digital twins that are scalable, sovereign, and AI-augmented. The literature does not yet offer a stakeholder-grounded account of the barriers. This paper reports a reflexive thematic analysis of 11 semistructured interviews with experts. The sample spans industrial manufacturing, automotive, telecommunications, public infrastructure, 2 platform or studio vendors, a research institute, a technology consultancy, 2 universities, and an industry association. The transcripts were coded collaboratively by 3 researchers who reached consensus through structured discussion. The qualitative analysis is corroborated by a Likert layer reported alongside the themes. The analysis identifies 8 master barrier themes. Interoperability across data formats and standards is the central constraint. Content creation is the dominant scaling bottleneck. The remaining themes cover hardware and platform volatility, the absence of a shared immersive user experience grammar, the role of artificial intelligence inside the runtime, trust and explainability limits, open source as a sovereignty question, and the demand for ready-to-run workflow scaffolding. A single-source observation concerns the erosion of opensource community review quality by AI-generated commits. The themes are translated into 7 candidate open-source building blocks that would relieve the common barriers. The contribution is empirical and forward looking. It is intended to guide open-source contribution priorities in the European immersive digital twin community.
