The current GraphCMS editor UX is fine for simple models, but starts to get unruly for complicated docs with lots of fields. Other systems I’ve used allow you to group fields into tabs, separating them into areas of concern. That can really help organize the editing UX, so that it’s less daunting.
I’d like to see the model editor have a button to create new content tabs, where I provide a name, then rag-and-drop fields (new or existing) into the tab I want (maybe just be another drop taget area in the existing UX), in the order I want. Then when a user is editing a record, they would see the tabs appear just under the existing toolbar with the fullscreen/close/draft/save buttons.