Today SweepTag generates QR codes and Code 128, which between them cover the large majority of what people label.
The candidates for next are EAN, UPC, DataMatrix, and full GS1 standards. Each is real work, and GS1 in particular is a specification rather than a barcode.
If one of these is blocking you, say which and what requires it — a retail requirement, a customer mandate, an existing scanner fleet. A concrete blocker beats a preference, and it moves things up the list.
(Scanning already reads EAN, UPC, Code 39 and more; this is about what SweepTag generates.)