I don’t know how to phrase it exactly, but having more presentation options would add to ACF’s already excellent presentation. I’m thinking about being able to nest blocs and rows into tables, tables into rows, etc. More options to build certain parts of the admin UI.
Attached is an example (very rough Photoshop) of something I have in mind, a scenario that I would use all the time if the feature existed. The first image is the UI with current ACF capabilities, the second one what I’d like to do with it.