I can find very little info about the Gewiss/Domotics zigbee product line. That seems odd given the knowledge-base here and at ST.
Sorry we don't live up to your standards. LOL. You are looking for info? You have the manufacturer's website. What more info could you want?
I've search some months ago for the 1526 smart plug (more compact than Tradfri) to give it a try but seems that it's impossible to find it for sale..
Zigbee has been used in commercial and industrial equipment for many, many years. Since Zigbee is an open protocol, manufacturers were under no obligation to comply with any interoperability standards. If any of the devices are interesting to you, I would call them and see if you can get a sample.