Experiences with Combi-box? Similar designs?

Hello, I don't have much equity and while browsing the internet I came across the website of the Austrian company Combi-box. Has anyone already had experience with this company or similar construction methods of houses? In principle, it seems to be a good and cost-effective option, or does anyone have further tips?

In theory, it sounds good. How do you get water / sewage into your box? How do you get them straight onto your property? You quickly end up with a concrete slab including connections and so on. A company in my area has been using such containers as office replacements for 20 years. The employees working there are satisfied.

According to the manufacturer, only spot foundations and a frost barrier are necessary for the construction. I think, as with every house without a basement, the connections are then installed there?

I want to bring this thread back to the surface as I am also considering [combi-box].

Are there any new experiences with this company or construction method?