It could be, if someone who's more of an electrical engineer than I am decided to lay out a board (and an enclosure)...
I'd take a stab at it myself, but the thing is that mains current is involved... I don't feel super comfortable dealing with that, both from the perspective of my own skills and from the perspective of risks I'd be comfortable passing on to other people. If I was selling it, I'm pretty sure I'd either have to get it UL certified or else include a big fat "if you kill yourself with this, you can't blame me" waiver.
Of the remaining options, one would be to combine it with something like this IoT power relay from SparkFun, which conveniently encases all the high-voltage stuff. Trouble with that is that you'd have to plug a wall wart into the thing to drive the microcontroller when the Mac isn't on, and that's kind of cumbersome. Another might be to figure out how to combine it with an ATX power supply mod and have the microcontroller control the power-on pin... but you probably can't fit one of those inside a compact Mac, and those you could fit it inside probably already have soft power, so the potential applications are limited.
Anyway, as of right now, it's just firmware, hoping someone will come along and uplift it into a full-fledged product. If anyone wants to do that, be sure and talk to me, I'd love to help in any way I can.
