Well, one of those threads is for steelseries, the other 2 are specifically for Razer.
That first link, though, you replied with a fine idea, "The vivaldi devs can't possible do this for every device, and having an open interface would let the community share plugins much faster." -That, I would vote on.
I do have to say though, I'm not surprised at all these requests.. Viv kinda dug themselves into that one when they supported Hue. Once you add one of them....