Seems more of a mechanical setup, rather than this guy's video. Like put a kill switch ON THE PATH (i.e. before signals reach) the "Okay iPhone, register this failed attempt" destination.
Other commentors have pointed out that the PIN/crypto stuff is handled by dedicated hardware designed to resist tampering, probably pretty much state-of-the-art. The issue before was a software issue. Now that it's fixed it's very hard to completely hack the hardware and would have to be done to each phone individually: https://news.ycombinator.com/item?id=10424439 I'm not an expert, but I imagine intercepting the signal would be just as hard, as the signal is contained within one tiny chip and it might not even be possible to reliably modify a circuit on that scale. You can't just replace the chip with a no-PIN version either, because it contains a unique crypto key to the data you presumably want from the phone. This also makes modifying the chip difficult, because if you screw up you could lose the key.
[0] https://www.mdsec.co.uk/2015/03/apple-ios-hardware-assisted-... [1] http://forum.gsmhosting.com/vbb/10720367-post1.html