Wait, what is it about exporting only one variable at a time that makes it possible to determine dependencies statically? Why not two variables? Or three? If you're determining dependencies based on variable names it seems like that would be possible.
You're right, it's more due to the fact that Observable requires you to explicitly export variables. However, limiting it to one has a couple advantages:
1. You don't recalculate other variables if only one needs to update. For example, if a cell exports two variables, and a dependency of one of them updates, you're forced to re-evaluate the whole cell.
2. I think the UX plays out simpler if you limit it to one variable. It basically reads like `myVar = {...}` at the top of the cell. It's a bit trickier if you try to support exporting multiple variables at once.
3. If you find yourself needing to tie several values together, you can still manage it by exporting a single dictionary value!
