Hi Gilles,
as far as I know, installing DW onPrem in private cloud environments is officially not supported.
Regarding Azure and AWS, I received an official statement from DW Support Team - it might work on the platform, but it is not supported by DocuWare.
Personally, I have one customer using onPrem on a single AWS Server, which currently works fine (7.9). I suppose issues with MSMQ will occur if you split the system on multiple Servers, which is probably the reason why it is not supported.
Hope this helps.
Greetings from Germany,
Simon H. Hellmann
DocuWare System Consultant