Enable mirroring on iPhone 4 (over-the-air) Through a cydia tweak or otherwise, is it possible to enable over-the-air mirroring for unsupported-by-default devices, i.e. iPhone 4, iPad 1 et al.?

You would think it's a popular question but all google results result in a dead end. The closest I've come to finding an answer is this topic, where an user claims to have come up with a solution, but then dies*.

Considering people managed to even port Siri for the iPhone 4, I'm sure someone must have made a successful attempt at enabling mirroring, which I guess only involves flipping a switch, i.e. no authorization checks, proxies, and missing binary files here. What I'm trying to say is I'm surprised there's nothing out there.

*or which is more likely, goes offline and refuses to share, whatever - the point is, no solution is given.
There's nothing that does exactly what you're asking for. However, this should be similar. I've stumbled upon it in Cydia a few times, but never bothered to try it, because AirPlay just never appealed to me. It's not explicitly AirPlay Mirroring, but it does the same thing. There's also a package called Display Mirroring and DisplayOut found in Cydia, and they enable mirroring, but it's not over-the-air (you have to use a VGA adapter). There's also another Cydia package called AirServer, and it allows your iOS device to receive media from your Mac or another iOS device through AirPlay.