The original topic was closed so now I am making this new one under Audio Gear Talk instead of Support.
I had just wanted to add that I have now had both the USB2 card and the Net2 cards installed, and the unit has been properly recognised by Roon.
I cannot say if there is a specific sonic improvement as I have the audio memory of a goldfish, but it sounds great (as always) and now handles DSD128 on the ethernet input without converting to DSD64, without displaying weird things like DSD4x, and without producing a hiss that it had started to do with recent firmware.
It also now accepts volume changes from within Roon, which as I recall it not do previously.
So definitely a win, albeit a rather pricey one.