Sadly, it wouldn't be possible with spider. You can't exit the browser while whatever ROP chain/binary is running, so it wouldn't be possible to return the game to do a recording. And streaming is even more so out of the question.
Well, just being able to do it like Pokemon injection, "Home -> Camera -> Scan QR code" would be good enough for pretty much all games that don't have Miiverse screenshot possibility.
And like I said, it is somewhere in memory, which is how both Miiverse and Notes have access to both top and bottom screen of a paused, running game.