At the moment, there is no means by which to adjust the top and bottom margins of the logo showcase in the configurator without adding custom CSS.
If you require a slim logo showcase (just logos with no header and minimal margins/padding top and bottom), the only way to do that is by adding negative values to the margin CSS. This is not ideal and is problematic with responsive design, requiring various @media queries to get it right in most cases.
The ability to adjust top/bottom margins without -value in custom CSS would be very useful.
Thanks