Do we have any idea what the quiescent power consumption of this dc-dc converter is meant to be?
It needs to maintain 1.5V not just into a heavy load, but also a very light one. Most battery powered devices spend most of their time switched off, or at least, in a standby mode where their consumption is microamps. Draw more than a few uA when the device is off, and you're doing more harm than good.
The marketing, and perhaps the application itself, isn't doing justice to what could be some genuinely worthwhile technology. Perhaps they do indeed have a notably efficient, small dc-dc converter, which is cheap, robust, and has extremely low standby power use? That in itself is a really useful piece of technology, just not for use in this particular product.