Feature Request: Extend crop pages feature

[BigMike]

Hi, I played around a bit with the crop pages feature today.

First I was a bit confused about the "constrain proportions" checkbox - because it doesn't really constrain the proportions, but sets all margins to the same value. But if the original paper format isn't quadratic, the proportion changes.
In addition, this checkbox doesn't affect dragging the boxes with the mouse at all. So, if constrain proportions is checked, I can't resize the boxes proportional using the mouse.

Please change the behaviour, that also dragging the box with the mouse will lead to a proportional box and that it's really "proportional".

Also the method to enter new margins manually is a bit inconvenient. At the moment, after entering a number, the curser jumps always to the beginning of the edit field. It's impossible to enter e.g. "1.5" at one time without repositioning the cursor.

Last wish: Could you please add "All boxes" to the box drop down, so that it's possible to change all box margins at one time!

Thank you,
Mike