That's true, but that sounds more like an additional layer to communicate charging info, negotiate which devices should get more power, etc. I do half-suspect

That's true, but that sounds more like an additional layer to communicate charging info, negotiate which devices should get more power, etc. I do half-suspect Apple probably tried coming up with a better solution (e.g. one not involving a charging mat), but ran into technical (probably laws-of-physics) challenges and went with Qi instead, because otherwise there's really no reason they couldn't have done this earlier. Or perhaps they just needed the time to re-tool for a glass case, who knows.