The idea is to place the receptacle into the spacer frame. 2.x mm height, sufficient for e.g. micro USB - maybe. The USB receptacle used on N900 needs a ~3.5mm height (incl PCB, ~3.0 without), so we need to find a "low profile" variant if we want to implement this. Or we request another tiny mod to the N900 case, like already needed for the micro-AB receptacle we use instead of the original. /j