UPDATE UPDATE:
Took the Meanwell over to my TT and its 660 ah battery bank (6 GC2s). Shut off the shore power, turned off the charger function on the Prosine and used the inverter to draw the batts down to 12.5v.
Set the Meanwell to 13.63v and applied it to the batts for about 20 - 30 mins. Every few minutes I would check both the voltage at the meanwell studs and the voltage at the batts. With full load on the Meanwell showed a steady 13.60 - 13.61 volts. Voltage at the batts rose quickly from 12.5 to 12.6 or so, and then slowly climbed to 13.60 when I finally got bored with the experiment and declared victory.
I do believe this particular unit is fully adjustable to a much wider range than the 14.3 -16.5 published in the specs. I'll keep monitoring it, but it appears I have a reliable 13.4 amp power supply at 13.6v (or even lower), as well a dandy boost charger at 14.6--or whatever.
At sixty bucks delivered I feel like I stole the thing!