Exactly, this would greatly reduce the ability for scammers in "urgent" situations, but for power users who flip the switch on day one it would rarely be a problem. What would be terrible though ... is if Google made it require a network connection or Google approval.
1 day is not longish. That would greatly harm apps like F-Droid. You'd have to go through it every time you want to update your apps.
He said one-time.
Yeah, just to turn on the mode.
Perhaps make you do it again after each major OS update, or once a year or something.