Nobody in FBI would give a damn about leaking the patched OS image: it's Apple's reputation on stake, not FBI's.
There is nothing of value for the FBI to leak.
This is the huge difference between this order (which I can live with) and blanket encryption backdoors using key escrow or other crap (which I'm absolutely vehemently against and willing to fight to the teeth)
That is completely not true. There is no way to make such a thing that can only work on one particular phone. There will be some point at which the compromised firmware image checks to see if it's that device, at which point it would be possible to change that to whatever device you want.
"This is the huge difference between this order (which I can live with) and blanket encryption backdoors using key escrow or other crap (which I'm absolutely vehemently against and willing to fight to the teeth)"
No, there is absolutely no difference between those two.
The technique that makes this possible is described in Apple's iOS Security White paper, page 6 ("System Software Authorization"): https://www.apple.com/business/docs/iOS_Security_Guide.pdf
This mechanism explains why you can't take an old release of iOS off a different phone and copy it to yours.
Not LEOs.
