For anyone interested, I have setup a test version of the Parent Driver that includes a Language selector in the preferences of the parent device (see link to the code below), but PLEASE KEEP READING before using this code.
The background to this is that I used someone else's code to get me started and that included passing a language code of 13 when performing the authentication step. @mikkomattip has reported issues with the language changing to Swedish in the MELCloud mobile app following the setup of the HE drivers. @jasper also reported that if the language setting was taken out of the authentication step the language was changed to English. Hence the decision to include the setting.
The reason for "shouting" earlier to read on is only that from the list of languages Jasper kindly provided, Swedish (which I believe is Svenska), has a code of 18, and the language code 13 that has been used in my code to date, is actually listed as Norsk. So I guess I would just warn people that this may not produce the expected outcome and may need some adjusting after some testing.
Simon