If you send the shocks to be refurbished, of course the valves will be fixed if needed, so I don't really understand why your planned experiment makes sense.
You must be aware that the EDC system does not activate if there is any error.
The light on the button does not indicate if the system works properly, but only that the ECU has power.
In regard to the diagnosis which defintely makes sense you must know that EDC is to my knowledge the only ECU in the E38 that does not support OBD interface which most interface kits do require. So you need to use an interface kit that supports ADS instead of ODB.
I have one which I can switch to use either ADS or OBD.
Without such ADS support INPA will indicate "no connection to ECU".