FF is considering implementing something in this space, yes. Note that there are at least two proposals for how this could work: one that is already deployed v

FF is considering implementing something in this space, yes. Note that there are at least two proposals for how this could work: one that is already deployed via a polyfill on various sites and the Google one. They have various functionality tradeoffs, and unfortunately Google decided to make up a wholly new thing instead of improving the existing thing...