Ah, ok, so do I understand correctly you would sort of like a visual preprocessor for programmatic model data?
And specifically ”whatever xml”, not, say STEP, or , openscad code, python code (via using cadquery) or anything like that?
Do you know your final output format?
I would like a way to take a 3D model which has been made in an interactive tool such as your tool or BlockSCAD, then export the descriptive representation (so the 2D and 3D geometry and parameters and instructions for interaction) as an XML file (BlockSCAD does this as its "native" format, allowing one to save a design locally and reload it.
Then, I would import that into my project, parse the geometry and instructions for processing it so as to create a 3D model, then I would work through the toolpaths necessary to cut the part thus described using G-code. Or, at least, that's what I would like to try to do. I'll have to give it a whirl w/ BlockSCAD if nothing else.