[dwroberts]

If you use a tool like Atmos (https://atmos.tools/) you kind of fix this issue already for free - because it takes the place of the root module, it actually manages the state of each sub module separately (they each have their own individual state file rather than being converged into one).

[lawnchair]

I don't think it fixes it. Atmos makes splitting and managing multiple states easier, but it still splits the graph. It doesn't change the underlying execution model.