Using Kleopatra should be possible for people using 400 % magnification.
For testing with 100 % magnification this means:
* All involved dialogs should still be usable with keyboard only if the width of the window is reduced to 480 pixels (i.e. 25 % of FullHD width).
* No UI elements should be cropped/clipped.
* Horizontal scrollbars are avoided as much as possible.