What I don't understand, though, is that these were for "digital signage systems" according to TFA. You're not running Windows 10 Pro on an Atom board and a large illuminated digital sign with 25W PoE. Maybe the signs were smaller than I'm thinking? Like tablet-sized? But if you're needing to run power for a display, why not just power the whole system from that?
Those must've been the server Atoms or the later models that aren't actually all that low-power, as the ones I'm familiar with are well under 10W.