An option for resetting the Crop to the original.
Kind regards,
Jerome
I understand the present Crop function is in the minimal achievement state.But to be honest, it’s not hard to reset to original.Compare to other urgency suggests, maybe will perfect this in 4.0 of next year.
There is no precise way to reset.
But I understand that this is not the most urgent issue, just wanted to bring it to your attention 
By the way, the crop interface has a gray to white border in the edge of PDF area. You can shift the sets to this border for reset.