Hello @ianh, This is essentially the same issue [as this one](https://github.com/mdaines/grammophone/issues/25). I've used that feature to collect a bunch of grammars [here](https://github.com/mdaines/grammophone/issues/26). I think it would be useful if the [owl playground](https://ianh.github.io/owl/try/) could support that too.