While I appreciate the intent of the amendment, I note that this is exactly why the abridgment of the “clear days” required is in there, so that if the medical or nurse practitioner felt it were likely that the person was about to lose their capacity, then that time could be abridged to address that issue. The whole idea here is that the person is given an opportunity to change their mind. That's what the point of the reflection period is and this amendment—saying that the person only has to have the ability to withdraw the consent if they still have capacity—would fly in the face of the other provisions and safeguards that are in there, including, in particular, the abridgment clause, which was put in there for exactly the reason that she is concerned about.
