What kind of processor does the Diesel-ECU uses ?
The same one the the latest petrol ECU ?
Then maybe a bool-loader can help?!
Btw.:
A Subaru dealer told, the standart Subaru diagnostic tester got no update to communicate with the Diesel-ECU.
Not for diagnostic and also not for falshing
German OpenSource-tool FreeSSM is able to communicate with Boxer-Diesel.
Maybe this can give hints to update ECUFlash/RomRaider for diagnostic ?