No supports necessary, but due to the large size there might be some warping. The switch-plate came out not completely flat for me, but that was not an issue because it pulls itself straight when you screw the case together.

The USB cable attaches to the left side of the keyboard, so that it can be conveniently be used with a tablet like an iPad.

To assemble the case you need six heat inserts for M3 screws and six M3 screws of a suitable length.