However, unlike in ArcMap, the Und/Redo buttons are not available once you have applied your edits.
In ArcMap, my understanding is the Undo/Redo buttons are only available for undoing/redoing edits when editing versioned enterprise data. If the data isn't versioned, then the Undo/Redo buttons don't undo or redo edits; they'll just undo/redo the last non-editing task, like undo removing a layer from the map.
In other words, undo/redo is the main reason we versioned our data.
Edit: Oops, disregard, I misread @MichaelTrust's comment.