How do I Change the "Macro Abortion & Notification (on Action Timeouts/Failures)" Default Behavior back to "Off"?

There is no way to change the defaults (well, you could use @DanThomas’s KMFAM macro).

You can select a set of actions that all have failures and control-click on them to change them all at once. But only if all the macros have failure modes, otherwise the menu will not be available if some actions don’t.

What specific action are you using that you regularly have to turn failure reporting off for?