The catch is that attackers can redefine accessor methods globaly, because those are part of the object system, and do run modified on load, but they cannot red

The catch is that attackers can redefine accessor methods globaly, because those are part of the object system, and do run modified on load, but they cannot redefine "while", which is a built-in, one of the few reserved language key words. At least I hope they can't. Of course that does depend on implementation details.