Hey Slimboyphat, if that parameter is not in your material config, it should have been overwritten by the defaultparameters.xml you mentioned.
Quoting Exocad Wiki:
"If no global parameter is entered in the material configuration, DentalCADApp uses the parameter from the defaultparameters.xml file.
Global parameters from material configuration have higher priority than defaultparameters (they override defaultparameters).
To edit global parameters, click Parameters, check the parameter list or search for desired parameter, choose the parameter and edit Global default value (Min, Value, Max, etc.).
You can adjust Parameter settings, e.g. hide some specific parameter from user or mark it as an Advanced parameter and choose for which restorations is this parameter available. Remember to press the Save button to complete the process."
Maybe there's something hidden in the Material Config or it's just bugged?
Checking further
edit: more of this stuff hidden behind reseller/OEM settings, not publicly availlable. Maybe ask your reseller if he can activdate this.