>The dedicated AES hardware extensions in ARM and x86 cores are probably the same logic anyway, so it shouldn't matter too much who decrypts the data. Maybe it's a tiny bit faster with the T2 though, because then the CPU doesn't necessarily have to pipe all the data through it's buses for decryption then. But that is more or less a feature of having a dedicated separate chip for it, and is thus not tied to the question of whether that chip uses ARM or x86 or any other ISA.

I don't really see how that would help, CPU i/o has to handle the exact same amount of incoming data encryption or not. Maybe a bit less RAM impact though.