Flow automatically filters keys corresponding to models compatible with the SE training_frame.
This fetching logic is done in FramesHandler#findCompatibleModels.
We may want to add a similar methods to find compatible grids as well (+ probably one parameter at the API level to activate this).
Also, the current filtering logic is pretty strict: all models should have been trained with a frame with all columns being present in the SE training_frame. We may want to loosen this restriction as it is not a true requirement for SE.