>non-information-leaking-boundaries

Every one of the recent leaking boundaries were assumed to be non-leaking. You cannot just inject "non-leaking" into a statement and assume that solves anything.

Sure, but you can mitigate against all known attacks. You can also mitigate against the class of attacks by, for example, not allowing multitasking and forcing single task to completion (within a dedicated core for a subset of operations).