Though it is a great idea, I believe it will break the workflow on the field group editor page. It also can be more of an obstruction than a helper, especially for the experienced users and for the end-users. That’s why most programs provide a documentation somewhere else, not in the program itself.
I think it will be great if it is packaged as an add-on, so you can deactivate it when you don’t need it. Maybe you or somebody else want to create it?
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