It would be a daunting idea to have this interpretation of BLANK! if not for all the other entangled work.
Vanishability permits pieces of your code to more easily communicate "nothing was there". Hence a mechanic for communicating vanishability (without accidents!) is foundational to allowing something like this to integrate into the system.
This is the linchpin:
https://rebol.metaeducation.com/t/why-comment-vanishes-but-not-eval-of-comment/2563
If you truly understand that, then you understand why a feature like BLANK! has legs in Ren-C.
