(Stones, trees, Bushes, metal, obsidian, crystal, misc such as silica pearls.) If we are talking raw numbers then my idea would actually save on server memory, approximately 11% less values to keep track of. Especially for single player where your system is both the client and the server...
Metal Tree Platform Metal Triangle Ceiling Metal Triangle Foundation Metal Triangle Roof Metal Water Reservoir Minigun Turret Mirror Moeder Flag Mortar and Pestle Motorboat Multi-Panel Flag Oil Pump Omnidirectional Lamppost Painting Canvas Plant Species X Portable Rope Ladder Preserving Bin Pressure Plate ...