Optimized for H2C - Expandable Plate Holder

Description This is a fully redesigned remix of the original Expandable Build/Cutting/Laser Plate Holder H2, focused on reducing material usage and print time without changing the core concept. The key idea: each stack shares its structure with the next one. Instead of every module being a full standalone unit, the top of one stack becomes the base of the next. This allows the design to keep the same functionality while cutting unnecessary duplication. The result is a cleaner, more efficient system that uses significantly less filament, fewer parts, and less vertical space. Additionally, the assembly has been simplified by switching to through-holes for the screws. This makes installation easier, more forgiving, and faster compared to the original approach where it was very tight. Key Improvements Half-height modular design Each unit is reduced to ~50% height compared to the original. Shared structure between stacks Every new stack reuses the previous one as its top — eliminating redun