If a user is under blocked under 3RR, allow a button to appear under the users page that directs the user to the policy. The button questions the user to agree to stay in accordance with policy and not edit the specific page for 24 hours. If the user agrees and presses the button, the block is undone. This allows the user to continue to edit other pages. If the user presses the button and resumes to edit the specific page, the block is reinstated for a duration longer than 24 hours.
Most admins will not block unless the person has been warned of the 3rr. I have often seen people continue to revert after being warned. Allowing someone in that situation to simply press a button and go on makes the prior warning toothless - they have just been given that opportunity and have chosen to disregard it.
On the other hand, many admins who block are willing to unblock if the person who was blocked emails them, apologises, and promises to stay away from the article. With 600+ admins, it's actually TOO easy to shop around for someone to unblock you.
As it stands right now, the system allows people to do what you are asking for. However, instead of having to convince a button that it was pressed, you have to convince a real person that you mean well and did not intend to break the 3rr. I find the current system much better.
Ian (Guettarda)