It appears that not all discovered values are being advertised during the startup routine. Only the values included in the definition files are advertised. For example, the Kwikset 914 lock never raises ValueAdded for its "Lock" value, but everything else defined in the device database's file (including all 30 lock code values) are.
Since this library is just wrapping the native OpenZWave library, and you confirmed the event can actually fire (confirming the wrapper works), this is probably better to ask in the OpenZWave repo.
It appears that not all discovered values are being advertised during the startup routine. Only the values included in the definition files are advertised. For example, the Kwikset 914 lock never raises ValueAdded for its "Lock" value, but everything else defined in the device database's file (including all 30 lock code values) are.