Observations

Yes, it does. But it is parametrized with either an open or closed row of effects and thus Eff (console::CONSOLE) doesn't compose with Eff (fs::FS). By opening and closing the row and adding and removing effects I can control the composability. This is also not fine-grained enough (esp. with the "inflation of effects" when everybody and their grandmother invents new type of effect which implicitly may include others) but it's much, MUCH, more fine-grained than IO() which is just "some IO" who knows what it does.