This paper discusses the utilization of a wearable Mobile Mapping System (MMS) (Gexcel HERON MS TWIN Color) for an extensive 3D survey of the Doge’s Palace in Venice, highlighting both the potential and the challenges of employing such technology in architectural contexts to achieve architectural accuracy standards. In under seven hours, a trajectory over 17 km was documented, resulting in 101 scan pathways and over 30 billion data points. To attain the necessary architectural precision (1–5 cm), the MMS was integrated with static laser scans utilized as Ground Control Scans (GCSs), and data processing was performed using Heron Desktop, involving extensive parameter calibration and manual trajectory optimization to reduce SLAM-induced drift and misalignment. The study identifies significant issues such as the evaluation and mitigation of drift errors, as well as extensive data management, providing practical solutions and underscoring the essential role of human experience in the processing phase. Although wear-able MMS demonstrates significant potential for swift, extensive architecture documenting, the necessity for hybrid methodologies and meticulous preparation is crucial to achieving the elevated accuracy requirements mandated in cultural heritage contexts.