You layer together "Components", each is just a single script that exposes some attributes and/or UI props.
gist.github.com/mattdesl/b7c96…
Code below — you could imagine the DrawPoints and DrawMesh as being built-in with the toolkit, or perhaps installed from a library.
→ gist.github.com/mattdesl/d1083…
→ gist.github.com/mattdesl/2c595…
Trying to think of some other test cases that might be hard to implement with this sort of paradigm... suggestions?