I have done some detective work....
Antoine's bad luck in having to open his 250Pro (upgrade) is our good fortune, as he took a photograph:
The above picture shows two things of interest.
Firstly, the power supply looks pretty much identical to the one in the 220Pro picture at the start of this thread. So it looks as if some of the 1000Pro pictures, including the one I posted earlier, are most likely pre-production pictures, indicating a power supply with slightly more components.
Secondly, the ADH board on the 250Pro is designated rev6.01/6L. The ADH picture on Devialet's website, and some other 1000Pro pictures on line, also show 6.01/6L, see picture below.
The 220 Pro ADH board per the first picture in this thread is designated rev6.022/4L (could 6.022 refer to version 6 ADH for 220, or maybe just coincidence?)
The O'dA ADH board is designated rev6.0, presumably the very first of the V6 specification ADH boards?
Make of it what you will......