Multiecuscan

I've checked my vehicle (a 1997 Fiat Ducato 230 2.5TD, using a Bosch MSA11 7.9 ECU, #0281 001 224) on the supported vehicles list, and have found I can connect to the ABS (5.3) system only. I've been told that the Fiat Marea 1.4 also uses a MSA11 ECU (I don't know about the 7.9), but according to the list, connecting to it gets the user far more data. In the case of the Marea, you can query the injection, airbag, and ABS systems. Excuse this noob question, but why the discrepancy? Surely connectivity should be similar for the same type of ECU?? Which leads me to the main question. Where the list omits certain types of connectivity, is that to say that such connectivity is definitely excluded (it will not work, we've tried it, and no go!) or that such connectivity is untested (it may work, we can't say, if it doesn't don't blame us!)? Thanks for your patience ...