"This will be the most effective on platforms where we already use open-source compilers to produce the executable, to avoid compiler-level attacks as shown in 1984 by Ken Thompson."

Using an open source compiler does not preclude the attacks in "Reflections on Trusting Trust". The whole point is that a backdoor can be inserted into the compiler, such that no copy of the source code has the backdoor, but the binaries generated would (and would perpetuate through the compiler compiling itself.)

With sufficient sophistication--and by no means do I believe the world is this compromised--all tools used to inspect such a binary could also mask the exploit. Every tool could be colluding against you.