I can't think of a single benefit for a dual output to simply parallel two batteries together, unless it provides individual charging and balance control, and you're using them independently.
If you're connecting them in parallel after the fact then all benefit is negated.
If you're using them in series for 24v, then I believe you can individually charge the 12v batteries and that is an upside, however you can just buy a 24v scc, and if it doesn't balance the batteries then you'll just have headaches.