The MaxSens TestBed is a human-centered demonstration and experimentation platform for advanced Human–Machine Interface (HMI) concepts based on electrotactile stimulation (ETS). It allows users to experience how information can be conveyed through multi-pad ETS, supporting an intuitive understanding of alternative feedback channels. Guided demonstrations help users develop a clear mental model of the capabilities and limitations of ETS-based interaction. By combining wearable, multi-pad stimulation hardware with real-time interaction scenarios, the TestBed enables hands-on exploration of spatially distributed and personalized sensory feedback strategies. Focused on sensory augmentation, adaptability, and personalization, the platform supports exploratory demonstrations and early-stage evaluation, while promoting human-centric system design in line with DeepTech and Industry 5.0 principles.