This would be huge for repetitive elements in an architectural workflow (e.g. thousands of duplicate panels, beams, etc.) and would allow the user to modify the geometry without the need to re-enter the Grasshopper definition. Currently the Human library for Grasshopper allows users to reference an existing block in the current Rhino scene and bake block instances via xform translation data. What this usually means for us is that we would have to bake a singular object from the duplicate set, define it as a block, and re-reference it into Grasshopper to get the xform data and bake via Human, so in the end it’s easier to just bake the duplicates and deal with the inefficiencies of larger file sizes and the reliance on Grasshopper to update the geometry. The ability to define Grasshopper elements as blocks and bake them as instances would be a nice feature to have in Rhino 6.