Unless you are installing them as consumer units within domestic premises, then the reg you are worrying about does not apply - and if you did, they could be used within a suitable outer enclosure.

 Looking at the link, I assume these are for commercial/trade use and not going in cupboards under the stairs.... they do look  more like festival/ event type devices where the risks from getting wet or  loss of earth, outweigh the one about long term overheating and fires.

Mike.