On the back cover a USB is added. This USB is accessible from the side, so the knob handling is not affected by the USB stick. 

The USB extension from https://shop.levendigdsgn.com/collections/prusa-mini-mods-upgrade was used. The extension is put into the frame from the front and screwed from the back side. But the USB angled plug was to big to feed through the frame. I have to cut the lower frame to handle the angled plug size.

I have printed it upside with supports, but it may be better to lay it flat on the bed (also with supports).