Digital Light & Color

When Layout is Reset, it takes on its default landscape orientation, but the Background image is not removed. When the orientation before Reset was Portrait, the background image is doubled to fill the whole landscape layout.
My suggestion is to remove also the background image, but to preserve the orientation when Layout is Reset.

Also, an option control Landscape/Portrait would be nice instead of having to overwrite the Size values (which prefer the Landscape layout) to get the Portrait layout.

If units are changed to cm or mm, the Snap Grid and Display Grid values are just multiplied by 2.54. Having the page in cm or mm but the grids in inches or a fraction of an inch is confusing as the grid is off the rulers decimal values.
My suggestion is that the grid values automatically change accordingly to e.g. 0.5 cm (5 mm), resp. 1.0 cm (10 mm) or whatever suitable values in decimal system to prevent confusion and the necessity to change the grid values manualy.

And one more observation.
Selecting a panel by a click sets the whole Layout dialog flashing unpleasantly.
For example, when I organize several small crops to a test print patch, the Layout dialog keeps flashing until I am finished.

I fixed the Reset problem.

While I could add a button to swap width and height of the layout, this can cause problems if you have already defined panels and the end up outside the layout. It seems to me that both this issue and the units issue are best handled by defining a default settings file and other settings files for different situations.

I'll see what I can do about the flashing.