I'm also the developer of FluidCAD. It has an MCP you can wire to any LLM. It runs locally on your machine.

It is still missing features for splitting the model into parts, but that is coming in a future release.

https://fluidcad.io/

MCP config (node.js required): https://fluidcad.io/docs/cli/#fluidcad-mcp

It's a woodworking domain engine and parametric furniture builder focused on projects like bookshelves, cabinetry, and shop furniture. It works out the parts, joints, cut list, etc.

There is an MCP component in beta (https://shopspec.io/agents) that allows an agent to explore designs while the engine still does the math. To take a design to CAD, a project can be exported as DXF or as a Ruby script that rebuilds it in SketchUp Pro.

It's narrower than Shapr3D, but it might fit the projects you describe.