I'm developing a GUI with a large number of sliders that have been enhanced with some additional data fields pictured below.
The small fields allow the user to change slider limits. The slider value is displayed in the large numeric field and using this same field for data entry will automatically expand the slider limits if necessary. It would save some manual labor if copying the objects also copied the small amount of callback code in the several objects. Granted, I would still have to edit, but the process would still be faster and less error prone. This is obviously one of the trades between App Designer and direct GUI code, but for those new to GUI creation App Designer appears to be the way to go.