So, I ordered the case because I wanted to use the combination of PSU (DC-DC converters) and power supply (AC-DC converter). I was able to expand without problems, all running now with another, slightly larger mini-ITX Case no problems with i3 Board. Unbeatable price for 70W!
The case itself I do not use, came straight to the basement. Quality seems for the price quite ok. It makes a really narrow impression, ie + HDD fans might already be close.