After all that, it turns out I can get both a 100watt 12vdc unit and a 100watt 24vdc unit, for the same price (in Meanwell's LRS series). Not as compact, but I don't care right now.
Since you seem to know about these ... Two similar (smaller) Meanwell units just died on me (I think I might've shorted 'em together briefly, but it was just after a lightning bolt came very very close to the house, so who knows). Anyhow, when I power either one up, the voltage comes up and immediately drops out (over many seconds if there's no load). Is that something recoverable ?