The action steps added to the account folder json file (api/account/folder.json) would be inserted (if it exists) after globals and before any of the individual files.
At the beginning of the file workflow you could add two contracted nodes(global and folder) that are expandable and contain the steps. These steps would not be editable. Visually you could make them a bit traslucid by lowering alpha or something similar.
Double clicking on the nodes would open global.json and folder.json SC flows.
It would also improve the UX in the data pickers as right now global bindings seem to come out of nowhere.